Thursday, December 21, 2017

May, A Month of Revival

May brings so much action in the garden as the pace of spring quickens.

This arisaema species came to me from our friends in town but I am not sure what species it is and I don't they remember either.  I think it could be A. japonicum or amurense, but if an arisaema expert (I know you are out there) reads this perhaps I can get the correct identification.  It is a good doer in that it is permanent and multiplies into a nice clump.  It flowers the first week of May which is early since others like A. consanguineum arent even sprouting yet. Typical red berries are produced later in the year, each "berry" containing a single seed within.   Arisaema is one of several "collectable" genera which has a devoted fan club.   Some of the species aren't always reliable, skipping a year of growth or disappearing altogether, A. sikokianum being one of those.   Others such as Arisaema consanguineum are easy to raise from seed and fairly permanent in the garden if the tubers are planted deep in decent soil.  For many arisaemas it is best to raise the seedlings in pots and keep the small tubers dry and cool in their pot for the first year then plant out the tubers in their second spring before they grow.  Larger tubers can be planted deeper which is desirable as some species do not like deep freezing.  However this one is an easy grower, and our native Jack In The Pulpit, A. triphyllum, don't seem to need special treatment.

 Tall dark stalks with reddish flowers of Polygonatum kingianum rise from the ground, later on they will bend in an almost vine like way.  Since I have only one clone of this species thus far I dont ever seem to get berries which are often as attractive or more so than the flowers of many in this genus.  With time the rhizomes branch and spread out slowly.   The dead woody trunk nearby is one of two common lilacs that I killed off to make room for more choice plants in this garden.  I keep one lilac (Syringa vulgaris) on another side of the property on one of the borders simply because I like the fragrant flowers which come later in the month.  But in the garden S. vulgaris suckers and needs much maintenance to keep it in good blooming condition and to not let it overrun its neighbors.

Stout stems and dark clustered leaves signal the emergence of lilies.  In this area I have mainly Orientpet lilies, particularly Scheherarzade which I transplanted from the old house. Lilies here need to be sprayed with a systemic insecticide upon emergence and maybe one more time before flowering to kill lily beetles which would otherwise devour the plant.  These bright red beetles resemble an elongated ladybug without spots.  They are an invasive species from Europe that destroys any lily or fritillary that they find.  The adults eat foliage, lay orange eggs on the undersides of the leaves, then the hideous slug like larvae hatch out and do even more damage.  The larvae cover themselves in their own feces to make them even more disgusting.  I tried the hand pick and squash approach, but in my experience it is not efficient at killing them before they do a lot of damage.  Imidicloprid or any other systemic insecticide does the job far more thoroughly.  The grass, Andropogon eucomis, which is sprouting is a species from South Africa where it grows in moist highveld in summer rainfall areas.  Its rhizomes go deep enough for it to survive without winter protection but cold winters will kill sections of it.  But some pieces always survive and grow and after a mild winter like the past one every piece survives.  It is wandering more than I like so I have been removing some of it so it doesnt swamp smaller plants.  The white fluffy seedheads are modestly attractive as is the bold foliage but I wouldn't recommend it for a small garden.
Helichrysum basalticum (at least that is what I think it is) has done superbly in the "crevice garden".  My original seed grown plants flowered in the garden their second year then died after making seeds.  Seedlings came up in the patio crevices and there they do much better and do not die after flowering.  Some have returned in the garden where they were first planted, a few years after they were last there so I think the seeds have the ability to remain dormant for a few years if they so desire.  But if seed is sown most comes up fairly quickly as with most helichrysums.  The velvety silver leaves are reason enough to grow it but later on the bright yellow flowers add even more interest.
I have many kniphofia species in the gardens and they are quite hardy here.  Only a few benefit from added protection in fall.  This one is fully hardy and may be K. porphyrantha but I am not sure.  Kniphofia is a confusing genus and wild collected seeds don't come from plants with name tags so even the identifications that I do get with the seeds can be suspect.  They also hybridize even in the wild so that adds to the confusion.  Regardless I have a thing for these majestic plants, and from the first week of May till the first hard frost there will always be kniphofias in bloom somewhere in the house gardens.  This one is early to flower and will often reflower later on in the summer.   Over time the kniphofias begin to form clumps.  In early spring the tattered foliage of some species is best cut off, a chore to be sure but such is a gardener's work.
Calycanthus floridus begins to bloom with its spicy sweet scented flowers.  I grew this from NARGS leftover seeds.  Many people balk at the idea of growing shrubs or trees from seed but it really is not that hard.  Some bushes like this one can flower in three or four years from seed so extreme patience isn't needed to see good results.  Buying woody plants is often a costly proposition and most folks around here hire "landscapers" (the term is in quotes for a reason) who plant too many bushes and trees too close together so they look sort of okay right away.  It doesn't take long for the bushes and trees to grow into each other and become a tangled mess.  No imagination and a poor selection of common and sometimes weedy plants is what the homeowners end up with.  They also tend to plant tough but invasive species such as burning bush (Euonymous alata) and Japanese barberry (Berberis thunbergiana) which then invade nearby woodlands.  I have eradicated both of these from this property.
Meanwhile in one garden with a fair amount of shade Delphinium tricorne blooms.  This is a tiny species which is an ephemeral woodland plant of rich forests in the eastern US.  Normally blue, this one is more of a white with an icy blue tint. It will disappear soon after flowering.
I got some arilbred iris through the Arilbred Iris Society a couple of years ago and this spring several of them flowered. They are a class of iris that are crosses between some hard to grow desert species and the much easier to grow bearded iris.  I gave them well drained spots in soil amended with coarse sand and they did well.  One disappointment was that some plants showed mottling in the flowers and foliage which appeared to be virus infection, these I removed and destroyed.  I also was able to set seeds on a couple of them to grow more of my own.  The flowers are works of art with colorful blotches and veining.  I have not seen them around here but perhaps they are more commonly grown  in the drier western states where they should do well.   If not they should be.

On May 12 I took this photo of a tree peony I grew from seed with its first flower.  Not too bad I have to say, and it should grow larger with more flowers each year.  The flowers are short lived but beautiful enough to have inspired all manner of art in China and Japan where they are treasured.   Peony seeds are large and easy to plant but patience is required as they usually grow a root if kept fairly warm and moist, then they need about 3 months of cold to be able to grow a shoot.  So if planted in summer in the ground nothing will be seen above ground till the following spring, and sometimes one waits longer than that.  The seeds can also be put in moist sphagnum in small ziplock bags and after roots show, the bags can be put in the refrigerator to simulate winter (not the freezer, that will kill the seeds), then they should either be forming shoots or will do so after they are exposed to room temperatures.  Once the sprouts start, the seeds can be teased apart from the moss and planted in pots or directly into the ground.  First flowers on herbaceous peonies will take 3 or 4 years and usually 4 or more for woody peony species and hybrids.
A mild winter and a bit of protection from the coldest weather allowed this Gazania krebiana to survive.  It may be "Tanager" which is just a selection of a particularly cold hardy form from the interior Cape of South Africa where frost is common in winter or might be from wild collected seed, I have lost track of which. The flowers are usually orange and can be variable often with attractive dark markings.   Like all gazanias, its bright flowers open only in sunshine.  Two seed grown plants are required to get fertile seeds as all gazanias are self sterile.
Delosperma congestum in in full bloom by the first week of May.  It is the hardiest of the South African ice plants.  There is a white form, White Nugget, which I also have. It is among the slowest growing of the delospermas so ideal for rock gardens and trough gardens.   It needs a well drained spot in good sun and can be increased by seed which it obligingly sets.
More delospermas are coming into bloom as May advances.  I have a few different species that are in the shocking pink/magenta range and I find it hard to differentiate among them.  Some bloom mainly in spring, others will flower off and on all summer.  They are also self sowing so more appear and I would hardly be surprised if some hybridization is going on.  Most of my delospermas were started from seeds from the exchanges and also from the last time I went out to Denver and stayed at Panayoti's house.  He let me gather any delosperma seeds I could find in his amazing rock garden and also at DBG.    I cleaned them and gave him back some and and also sent many into the seed exchanges that year.  Delospermas are easy to raise from seed and many will flower their first year. I find it best to plant them in soil amended with coarse sand for drainage.  They don't like soils high in organic matter nor extreme cold and wet as the same time nor hot rainy weather in summer.   Extreme cold/wet can cause dieback but any piece that survives grows fast the next year, whereas prolonged heat and rain together are worse since a mold can attack and kill them.   If the mold appears (its obvious) it is best to remove affected parts and douse the spot with a fungicidal drench.
Delosperma sp "Firespinner" is an unidentified/unpublished species from the highlands of the eastern Cape of South Africa.  Panayoti brought back some from Kirstenbosch near Cape Town, as I recall, where it never blooms because it doesn't get cold enough there, but it has been an outstanding success in Denver and many other places.  It grows well here given the same conditions that suit most delospermas.   Its biggest fault is that it only blooms once but it is glorious at that time.  An occasional flower may appear later on, and it can be propagated by seed or cuttings.
Constantly keeping the mammalian critters at bay makes plants that don't appeal to rodents (including the super destructive large hooved kind) more valuable than ever.   Anything in the genus Allium tends to not have pest problems and they are generally easy to grow.  This is a hybrid or selection of Allium karatarviense from Brent and Beckys that is larger in all parts than the standard species.  Like the more common form it is reliable if planted in full sun.
Delosperma nubigenum is the yellow one below, it runs and does most of its blooming now.  The magenta one is another one from seed, perhaps a dwarf form of cooperi or one of the plants that goes under the name D ashtonii.
Or perhaps this is D. ashtonii, it has smaller flowers and pretty much blooms only at this time but it is a sheet of flowers and is a bit lower growing and has smaller leaves than the previous one shown of a slightly lighter version of this color.
A tiny dianthus, Dianthus arpandianus var pumilus, resembles a green pincushion studded with little pink stars.  I got this as a rooted cutting from our friends in town.  It is a perfect rock garden plant but is easy so far, I just need to make sure nothing tries to grow too close to it to prevent it getting overrun by faster growing things.
Catananche caespitosa comes into bloom, its a small thing from Wrightman Alpines I picked up a couple of years ago at the Stonecrop Alpine sale.
Aethionema grandiflorum came from our friends Alex and Lyn Kenner's garden.  I think it is in the nature of most gardeners to pass plants back and forth, enriching both gardens in the process. This is a rather pleasant plant with a neat habit and good pink flowers borne in abundance in May.  It will reseed but not so much as to ever want to be rid of it.   Even when the flowers are gone the narrow blue green leaves are appealing to the eye.
Papaver rhoeas, the Shirley Poppy, seeds everywhere by now and I let some of them bloom in the patio garden before I pull them up so they don't overrun smaller things that, unlike them, really need to grow in the crevices to do well.   All these poppies need is a place without too much competition and a lot of sun, and decent drainage.  They reseed and come up every year in various colors though the reds tend to dominate after a while.  So its a good idea to rouge out most of the red ones before seeding and plant new seeds sometimes of the strains like Angel's Choir that contain a lot of pastel colors to keep a variety of colors in the population.
Meanwhile at school the Melianthus villosus is resprouting.  It has lived by this wall of the building for many years.  It has flowered only once, but it was a real oddity, big green flowers that dripped black nectar.   The students like it because the leaves smell like peanut butter.
Pelargonium luridum has also done well for years in this protected spot by the building and will flower later on.  I am growing more clones of this species in pots with the eventual aim of trying some at home where a thick winter mulch to prevent deep freezing around the tuberous roots should suffice to allow them to live outdoors here. 
The same wall allows me to grow Amaryllis belladonna, a winter growing bulb but here its leaves are burnt back by severe frost and emerge in spring to grow out until late June or July, then die back.  I get one or two of them to flower in this spot each year in August.   This fall I got several big bulbs from a grower out in California and put some in front of our house but covered them with a wood chip mulch to help them get through winter.   It will be interesting to see how they do away from a wall, I do know the bulbs cannot be planted very deep so they need cover to prevent deep soil freezing.
Also at school the lovely Oenothera berlanderi "Siskiyou" is coming into bloom.  I would bring some home but for its wandering ways, it does like to spread far and fast if it is happy.  It likes dry sunny spots with little competition and it finds what it wants here.
Bearded Iris are beginning to bloom, I have one variety here that was inherited and I got rid of most of it, but I added some from my sister in North Carolina who inherited a lot of them with her house.  She had them thinned, then pulled up some and left them in a plastic garbage can that leaked for months.  The rhizomes were still in good condition when I visited one spring so I took some and planted them and these are the results.   I also have more that I got as a mixture of named varieties from Wild Iris Rows and I am very pleased with what has bloomed so far.

Papaver orientale, the Oriental Poppy, begins its brief but spectacular show in the front gardens.  I grew some from seed and moved them to the front.  They make deep roots which invariably break but can grow back if one doesnt get it all out. Root sections can also be used to propagate them.  The large bristly foliage is unpalatable to all critters and will disappear in the heat of summer, only to reemerge with cooler weather.
I picked up this plant of Silene asterias from Annies in California.  I have sprouted seeds before that turned out to be something else but this is the real deal.  A rather nice and easy plant so far.

Monday, December 18, 2017

Spring part 3

We are not even finished with April yet more things come into bloom.
These violas were grown from seed from Swallowtail Seeds I think, and I enjoyed the complementary flower colors of different plants.  They self sow as does the more common Viola tricolor, a smaller flowered purple and yellow flowered one that I have a lot of here.  Violas will take a lot of frost and still bloom, so they can be in bloom almost year round.

I  have a number of Epimediums here and some have done well.  They are a diverse group of plants mainly from China.  They are self incompatible, meaning individual plants will refuse to set seed, so more than one seed grown plant of the same species must be present if they are to make seeds.  However different species hybridize easily so an ever increasing number of hybrids are appearing since most gardeners grow a single clone of a given species.   They are good plants for shade or partial sun, preferring well drained soil. With time they spread outwards, some faster than others.  They appear to be critter proof and the flowers usually (but not always) hang downwards in shades of purple, yellow, orange, white, and pinks.  I admit to giving up keeping track of their names as there are so many species and hybrids of them.  Garden Vision nursery carries the most extensive selection of them that I know of and while they are not that cheap they are also a forever plant if they find your garden to their liking.

Anemone ranuculoides is a spring ephemeral from European woodands. Spring ephemeral plants grow during spring so that they can make food via photosynthesis, flower and make seeds and then go dormant by retreating underground when it is too shady and warm to for their liking.   They are adapted to make the most of the spring sunshine before the tree leaf canopy above them blocks out the sunlight.  I got these as dormant tubers at the fall Berkshire NARGS chapter sale.  Often getting plants from such sales means they came from someone else's garden and were very successful so they have extras to share.  That increases the chance that that particular plant will be a success since it is growable in the local area.  Admittedly most of the members of the Berkshire chapter live in far colder regions than I do (USDA zone 5 and 6 mostly compared to my edge of zone6/7) but our summers are not vastly different, rather their winter lows are much lower than around my town and my growing season is longer with an earlier frost free date in spring and a later first frost date in fall.

Tulipa vvedenskyi is one of my favorite tulip species because it has attractive blue green wavy foliage and huge bold flowers for the size of the plant.  These came back a second year from planting so I am hoping they will be permanent.   They are the  commonly available clone "Tangerine Beauty" but they will set seed which I have not yet tried to grow.   It might be interesting to see if seedlings would show some variation in color but it would probably take five years to see a flower from seeds.

Tulip "Fire of Love" has flowers are a decent single red but one grows this for the amazing foliage.
Double flowered (or peony flowered) tulips are quite showy if a bit less than graceful things.  Graceful is a more appropriate description for the candy cane tulips (Tulipa clusiana) that surround the double flowered tulips.  Tulipa clusiana is a good naturalizer and should come back every year so long as the rodents who love tulip bulbs are kept at bay.
Tulipa linifolia is a pretty little species that likes the same conditions as the Opuntia cactus in the photo--sunny and well drained soil.   It is smaller than many others but the bright red flowers call attention to it when it is in bloom
Basket of Gold, Aurinia saxatilis, is a plant I remember from my childhood.  Our landlord in Yonkers NY grew it in his garden, very likely having brought it over from Italy which is one place where it can be found wild.  It is considered to be a bit too vigorous by many rock gardeners because it can spread outwards to cover a lot of ground but it is also a very showy plant when in bloom. The grayish foliage isn't bad looking either.  My plants came from leftover NARGS seeds distributed to the local chapters that otherwise would have been thrown away.
This pink and white Lathyrus vernus is just as old as my purple one but is not quite as vigorous.  It is also getting bigger by the year and ejecting seeds when the two halves of the legume seed pod dry and twist to expel the small pea like seeds within.
Daphne jasminea (?) was obtained as a small plant from Wrightman Alpines during the annual Alpine Plant Sale held at Stonecrop Gardens in Cold Spring in late April.  It has amazingly fragrant flowers, a major selling point for most daphnes.  It is a slow grower as most of them are but pretty much trouble free so far.  Daphnes are known to up and die suddenly, often from a root fungus but this one is in a spot it seems to like and it slowly spreads outwards each year. Flowers appear sporadically through the summer but its main display is in late April and early May.
In the first week of May this most unusual dogwood (Cornus florida) bursts into bloom.  It is an old tree with some dead branches that I had removed.   I also had nearby hemlock branches removed so it could get more sun.  It is a mystery as to how this plant got here, because the closed flower with its folded white bracts creating a bird cage appearance is typical only of a very rare form of dogwood known as C. florida spp urbiniana which is native to Mexico.  It is very scarce in cultivation and I find it unlikely, but not impossible, that the former owners of this property got one and planted it.   It has been in cultivation decades before it was formally described.   It also might be an unusual mutant seedling dogwood that came up, there are other dogwoods nearby that may have also come up from bird dropped seeds.  I have seedlings of it coming along but it is too soon to say if they will have the same kind of flowers as dogwoods are outcrossers (self infertile) so the seeds of this plant have to have crossed with a "normal" dogwood nearby.  I am also trying to ground layer it to get a duplicate plant that will be genetically identical to the parent plant.  Without a doubt it is the most interesting and unusual plant that I found on this property when we brought it.
Mertensia virginica, bluebells, is another spring ephemeral that disappears very quickly after flowering.  It is native to the eastern US in rich forests.  White and pink forms are known but scarce but the blue one is quite nice and easy to grow.  Most members of the genus Mertensia appear to be alpine or shoreline plants accustomed to lots of sun but this one is well adapted to shaded woodland conditions.
Vancouveria hexandra is from the forests of the Pacific Northwest.  It is one of many North American forest plants with close cousins in East Asian forests.  Vancouveria is a small North American genus which is very similar to the much larger Eurasian genus Epimedium and likes similar growing conditions.   I got this plant from one of  the Berkshire Chapter plant sales.
Ok, this is cheating slightly as this Iris cristata is actually in the school garden.  It can be a miffy species to grow, when happy it spreads by very shallow rhizomes but it can also die back suddenly.  These were grown from seeds from SIGNA, the Species Iris Group of North America which has the best seed list of Iris species to be found anywhere.  Iris cristata is a woodland plant of the eastern US which can vary in flower size and color.  This one must get a lot of sun until it is swamped by larger growing plants later in the season.
Also at school but not yet at home are some plants of Rosa xanthina grown from seeds I got some years ago from The Fragrant Path.  They are quite thorny so the deer don't bother them and they can self sow on this well drained slope.   The yellow flowers make a brief but glorious appearance in May.   The Asparagus plant in front of the rose is descended from wild collected seeds from Siberia from a Russian woman.  I think her name is Alexandra Beutenko but I can't find any reference to her online so perhaps one of the readers of this post may be able to provide more information.  She collected seeds mainly from Siberia and Kamchatka if I recall correctly some years ago.   The asparagus may very well be a wild version of the well known vegetable A. officinalis, but whatever it is it is a tough plant with attractive lacy foliage.  Curiously despite having a few different seed grown plants in the school garden I have not seen the red berries on any that would indicate seed formation.  Asparagus plants can be male, female or bear both male and female flowers so perhaps all of them are of one gender.  I'll have to remember to check their minute flowers next time under one of our class microscopes.
Meanwhile back at home the primulas continue to bloom and two kinds of Camassia are in full bloom.  The blue one in the back is from one of the Dutch growers and were transplanted from my home gardens and I think it is C. quamash.  The pink ones in front are much harder to find, impossible really at this point in the US.   They were collected by one Lisa who ran a nursery called Buggy Crazy in Oregon.  I got bulbs from her years ago and continue to grow this exceptional form of this usually blue flowered species.  White forms are known but I have never seen the pink form offered by anyone else nor has she offered it recently as far as I know.  It is a long lived bulb but propagates slowly although copious seed is produced.  Her nursery is no longer around in the sense of having a regular website but she does sell occasionally on ebay under the name growingcrazy2 and she also sells on etsy I think.  She sounds like a colorful character who has little patience for neighbors with destructive animals that made it impossible for her to continue to offer the many fine lily bulbs she used to grow, and also for ebay's increasingly ridiculous seller fees.  I hope she finds more peace in her life as I really appreciate the wonderful bulbs and seeds I have brought from her over the years.  Many of us miss the great lily bulbs she used to offer, many of them the result of her own breeding efforts, but rampaging animals and a lack of law enforcement seem to make growing lilies on a large scale a very difficult proposition where she lives these days.  I once ordered a box of small leftover bulbs from her years ago on ebay, basically she crammed several kinds of bulbs into a small priority mail box and I planted them in the school garden where they flourish to this day.  Included were a couple of kinds of colchicum, some daffodils, dichelostemma, and some other odds and ends.  The bulbs were small as advertised but a few bloomed their first year and they all bloomed the second year and the colchicums in particular were a good deal.  They have grown and every September I get to show them to my students when their large flowers pop right out of the ground.
A closer view of the pink camassia.
This little ranunculus sp grows leaves in winter from small clustered tuberous roots but disappears soon after setting seeds.  I got it from a single seed that germinated from some leftover NARGS seeds years ago when I was a doctoral student at Cornell.  I used to go to some of the local chapter meetings and I nursed the seedling along in the greenhouses until I took it home and planted it.   It multiplied over the years by seed and tuber and I took some when we moved.  It does best at the edge of a garden (or in a lawn) since it does not like competition when it is in active growth.  Bright buttercups appear in May above the hirsute foliage.   I once found a name for it but have forgotten so I will have to do some more research and come back when I find it again.
By early May the Linaria alpina are beginning to flower profusely.  They may be hybrids with other species by now but whatever they are they are beautiful.  They like the cracks between bricks in the patio where I have established a "crevice" garden of sorts.  I find that certain plants do much better in these patio crevices than they do in the open garden, and these linaria, which come in several different colors, do especially well.  They will flower all season long but look their best in spring.   Copious seeds are produced and thinning of the offspring required so that the plants have sufficient room to develop properly.

More typical hybrid tulips of the Darwin sort most likely are in full bloom in early May.  Some of these should be good perennials.  With tulips it is best to try several kinds and see what persists in the garden as some tend to rot in summer when the bulbs prefer drier conditions.  Over time the survivors that are adapted to our climate will multiply and eventually will need to be lifted and separated to give the bulbs space to grow to flowering size.
Silene caroliniana var pennsylvanica is in bloom by early May.  It is a rather rare wildflower in this area but I know of two local colonies which this plant is descended.  I found one colony many years ago (and have written about it before) when I was a teenager exploring the woodlands nearby.  They still grow there but not in the same numbers as before decades later on thin acidic soils atop granite rocks that overlook the New York State Thruway.   It prefers sunny spots in rock crevices but this plant has done well here in a raised garden and even seeded into the patio below.  Plants from this population are mainly pink, but another population that a friend has taken me to in Connecticut has light pink to nearly white flowers.  I have some small plants from the latter as well that are well established and will bloom next spring and set abundant seed.  This species often appears on the seedlists from the UK but is usually an impostor which turns out to be Silene dioca, a European species.  I can see how one might mix them up looking at photos of the flowers but once you see both species there is no way to confuse them.

Here is the one that seeded into the patio below.
I decided to create a trough garden in the bird bath that came with the house.  Our Jack of all trades friend Lin who can build anything drilled some holes for drainage and I planted some plants from S Africa (Delosperma congestum with the yellow flowers), Asia (the crassula like plant with rounded fleshy leaves), a sedum I collected from the Taroko Gorge area on the way to Hehuanshan in the middle, and some sempervivums (Hens and Chicks) that I took from my maternal grandmother's house after she passed.   They looked pretty good when this was set up as can be seen and have done well.   The sedum has suffered some frost damage so I dont know if it can survive our winters but I have backup in my cold frame and indoors just in case.

The rare dogwood is looking splendid by the first week of May.
Meanwhile the double form of Ranunculus repens blooms en masse in a corner of the property where I let it romp around.   I got it many years ago when I worked as a urban garden aide one summer for Brooklyn Botanic Garden and it has followed me through the decades since.  It does not form seed like the single flowered form, which is a blessing as it really is a weed.  It does spread vigorously by stolons much the same as a strawberry plant does.   It takes some work to make sure it doesnt get too out of control but its worth keeping around for its beautiful spring flowers.   It is rarely available commercially even though it is so easy to propagate and has limited invasive potential since it cannot make seeds.
The aqulegias are also coming into bloom by the first week of May, all of mine are grown from seeds I got from the rock garden seed exchanges.  I have close to a dozen or so species at least and I don't know what all of them are but this one is probably one of the western US species or possibly a small form of A canadensis, the eastern US Columbine.  Whatever it is I like it and while aquilegia species are notorious for crossing with each other I find that many self seeded ones do come up that looking just like their parents. 
Spanish bluebells (Hyacintha hispanica) were here when we came and I brought a few form my old gardens as well.  They are tough and multiply quickly into clumps, to the point of being a bit aggressive when they are in actual growth in spring.  But being toxic they are impervious to pests and animals and guaranteed to give a nice floral display in early May.