Showing posts with label How To Garden. Show all posts
Showing posts with label How To Garden. Show all posts

September 9, 2008

Corydalis wilsonii seed

The tender alpine house Corydalis, C. wilsonii, has set seed late this year. This monocarpic Corydalis has interested me for a while,ever since seeing one in the Munich Botanical Garden's alpine house. There, it sets seed freely around the alpine house, but my plant, grown from seed acquired from a NARGS seed sale, has set seed freely, but has not spread anywhere, other then a few plants growing in the same pot where the mother plant has grown for three years now.
At the NARGS winter study weekend last year, I met Corydalis expert, Henrick Zetterlund, author of the monograph CORYDALIS, and horticultural curator at the Gothenberg Botanic Garden in Sweden. He suggested that I try growing Corydalis wilsonii in Tufa rock, a porous limestone often used to grow more difficult alpines in. HE advised me to sow the fresh see ( for Corydalis seed must be sown fresh), right in the crevices of the tufa rock. Henrick also said that Corydalis wilsonii, when grown in Tufa, will be more characteristic to plants grown in the wild. With it's notable blue, glaucus foliage remaing dense, and bun-like, rather more like an alpine, than plants grown in a traditional fast draining alpine mix.

So this year, since I have a load of Tufa ready, and some fresh seed, I shall try. The plants are rather ragged, but the seed capsules are still green, and reveal shiny black seeds when gently squeezed between the fingertips. I caught the seed pods just in time, since I caught sugar ants already stealing them for thier sweet sugar. Stay tuned to see if any of these grow. I set the rock in a tray of water, and now, the wait is on. IF I can afford to heat the greenhouse this winter, we may be blessed with some new plants!

February 18, 2008

The trouble with Lupines

Russell Lupines at the Chelsea Flower Show
The chatter amongst those in-the-know about lupines is that suddenly, they've become difficult to grow well. It's true, In 1997, anthracnose began showing up world-wide, in populations of Lupines, reportedly due to the commercial growing of Lupine species as a protein seed souce, worldwide. Anthracnose, is a fungus, spread by moisture dripping on t foliage, or soil born. Whatever the actual cause, if one wishes to grow award winning lupines, such as the Russell Lupine above, photographed at last years Chelsea Flower Show in London, one needs to take precautions.

It's not surprising that most retailers who sell seeds, fail to mention this problem. A problem that can be overcome by home gardeners if they take a few precautions which may seem elaborate, but necessary.


German seed supplier Jelitto, is the only source that I know of, but there may be others who can supply to the home gardener. You must get seed which has been heat-treated, and Jelitto has a patented Jelitto JET® process which renders their Lupine seed virtually free of Colletotrichum acutatum, or, Anthracnose. But, attack from other sources cannot be ruled out.


This is critical. Home sterilization is relatively easy, if you have an oven, some foil and time. OK....so what are a few worms in the All Clad! This weekend, in the thaw, I was able to dig up some soil from outside in the garden, and baked it at 400 Degrees F. for two hours, along with some sharp gravel. This, I mixed with some perlite to create my peat-free mix.


Common sense here, I simply soaked some seed pots and trays in household clorine bleach and water, 2 tablespoons per gallon (as if I measured!).

4. SOAK SEED FOR 30 minutes at 131 deg. F ( 55 deg. C). to kill any existing spores. This may reduce your germination rate, but it will be worth it.

5. PLANT SEEDS AND TRY TO KEEP SEEDLING FOLIAGE DRY. This is important, since you want to avoid spraying with a fungicide, I would imagine. Although, I try to practice organic gardening, I personally don't have a problem with Fungicides. They are useful if your plants are to be growing in a damp greenhouse for the spring, or outside in a wet area.

Other than that, it's easy! Lupines are magnificent when grown well, but understanding the issues they can now have, will help you if you plan on investing on some seed or plants at your local garden center. Don't expect to find this info on the seed packet or in the seed catalog from most seed retailers. Clearly, it will put people off.

February 10, 2008

Rare South African Lachenalia from Seed

Rare species, such as this green-flowering variant of the more common, L. aloides, Lachenalia aloides var.Vanzyliae can only be obtained by seed.

Now that a big part of my design book is finished, I can finally refocus on the greenhouse. Last Sunday was one of those fabulously sunny, yet cold, winter New England days, which, even by early February, can make the glass greenhouse feel like summer. The sun is already beginning too feel stronger, and as many of us gardeners note, subtle and not-so-subtle changes are ocuring in nature, signifying that winter is waning. I love this time of winter, February and March. I know, you might think I am crazy, but underglass, it's not mud season, really.
The plants which one can grow in a cool greenhouse are generally those Mediterrainan types one sees in the south of France, southern Italy, or California - shrubs and bulbs which respond in February to the increase in light levels. I was telling visitors yesterday, that March, is the season of full bloom in my greenhouse- how could I ever hate March? There is nothing, like sitting in a sunny hot greehouse, with three feet of snow outside, wearing nothing by shorts and sneakers, potting up seeds in the hot sun.
You can hear the birds outside, and when focusing on what you are doing, you could swear that you can hear lawn mowers and smell cut greass and charcoal grills maybe! but actually, that's the nicest part! you can't!
It's just you, the woodpeckers on the feeders, a hark getting cracnkiny high in the hemlocks about the pigeons in the coop, and you hear nothing else..., no kids screaming, no lawnmowers and no weedwackers.. nothing. Not even cars going by in the distance (of course, the Patriots were playing in the Superbowl, so maybe that had a little to do with it!). I'm sort-of not ia sports fan!

Usually, one must purchase and plant seed for South African bulbs which are winter-growing, in the autumn. A sowing in September or October, would guarantee a winter of growth, before thier inevitable summer rest of dry dormancy.
This year, I am taking a chance, and planting a collection of selected seeds in mid-season winter, these are seeds which I purchased on line, from Silverhill Seeds (a respected collector of rare, South African bulb seed, of wild collected species which are not available anywhere else. Although late, it is not impossible to get a years worth of growth on these plants, which are quite easy to germinate and grow, given that one has a cool greenhouse, or a protected area outdoors if you live in a mild climate ( like California).

All I need is a few months of strong growth, which I will get here in the northeastern part of the US during February to June. I have found that since December to January provides weak sun, I can usually "catch-up" many species in this later part of the season, and c an even continue thier growth until mid July, before drying off the pots, to provide a couple months of dry "winter", then restarting them a bit later than the other established bulbs - let's say, October.

This year, I am focusing of Lachenalia species, with 38 new species being added to my collection, and then, a few Moraea, Ornithogalum and single species which have captured my attention. The process for all, is the same, with the exception of a species or two of Lachenalia which demand pure fast-draining sand. I mix one large batch of fast-draining soil, which isn't too fussy, just Pro-Mix, a commercial peat-soil-less blend, sand, gravel and large perlite. The seeds are surface sown, then covered with gravel chips. It's large gravel, but it's all I have, so time will tell if this even makes a difference. The gravel helps keep moss and weeds from growing on the surface, since these bulb seeds will stay in the same pots for at least three years, before repotting.
Lachenalia species, wild collected rare species, planted three years ago.

Most of these species will bloom in 4 to 5 years, the Lachenalia flat, may have a few early bloomers in two years, and many in three.

December 17, 2007

Forcing Lily of the Valley Pips

Lily of the Valley Pips arrive via post

I am fascinated with things that fall out of favor, culturally and horticulturally. The list of forgotten plant favorites is long, fragrant bouquets of Parma violets scented that scented the air of railroad cars at the turn of the century, bowls of Anemones that once were the traditional Christmas flower, long before the Pointsetia made its way into cultuvation in the 1920s. Camellias, Chrysanthemums, and perhaps most lost of all, bulb pans of forced Lilly of the Valley. Once commonplace, featured in ads in gardening magazines right through the 1960's, for whatever reason, the tradition of ordering single plants of Convallaria majalis, known as Pips in the trade, fell out of fashion in the last quarter of the twentieth century. As a child I rememebered seeing full page ad's in my uncles Horticulture magazines, and I often dreamed of someday finally having money so that I could order them to grow in the greenhouse that I, of course, would someday build and own. Well, the day is finally here, except finding a source for Pips was more difficult than I imagined. Thanks to White Flower Farm, pips are available, I suspect that they are the last retailer in the US to carry them, and although a bit expensive, I believe it will be worth it. Most likely these pips are from a source overseas, either in Germany or the Netherlands. The only source I found was a Dutch wholesaler, and I would bet that they supply White Flower Farm.

The pips arrive safely wrapped in newspaper, and the simple procedure of planting them in moist soil is as easy as potting up paperwhite bulbs. The pips are large, not even remotely similar to pips dug from your home garden. These are at least four times as large, and have already been vernalized (kept cold in a false winter for a period of 16 weeks). All that needs to be done is to plant, water and wait.

15 Pips we're potted into a 10 inch bulb pan, watered and places on a plunge bed in the winter sun. The cool temps and moist air of the cold greenhouse will ensure sturdy growth and be early January, will deliver the fragrant white bells that say "june wedding' during the darkest days of the year. I can't wait!

November 11, 2006

Fancy Chrysanthemums

Like so many traditions, the art of fine Chrysanthemum growing is long forgotten in most of the world, replaced with growth-retardent hyper-pinched and fertilized monster-mums displayed in bushel baskets and then tossed into the trash like any disposable holiday decorations, the chrysanthemum has gone the way of fine English carnations, to even become lower-class supermarket plants with a status that often has no other plant lower.

This is ashame, for in Japan and China, the Chrysanthemum continues to to be an important part of the culture, with spectacular displays that continue today. In America and Europe, the lowly 'mum' has suffered a fate the few can ever pull out from. Until the twentieth Century World Wars, the Exhibition Chrysanthemum was grown for display and cut flower, and many private estates based thier entire autumn display season around these late blooming plants. The American Chrysanthemum Society, classifies Mums in categories that still reflect thier heyday, yet only one mail order supply house still carries the classic varieties (Kings Mums). Why not consider growing a ledgend, and bring back the Chrysanthemum. We did it with English Sweet Peas, but many other classic heirloom plants need to be resurected before they are gone to the compost pile forever. This includes many plants found on this blog - Scented Parma Violets, English Auricula Primroses, Japanese Chrysanthemums - one of the first plants ever cultivated by humans in China.

July 29, 2006

Repotting dormant bulbs: Bulbous Oxalis

The rarer and slow growing Bulbous Oxalis species perform best when repotted in the summer while they are dormant.
The highly collectable bulbous Oxalis species that hail from the winter growing areas of South Africa and South America are a far cry from the weedy pest that plague our gardens and greenhouses. This is an enourmous genus and are truly sought after by plant collectors. Once you try a few of these winter growing and summer dormant species, you will be hooked and then the collecting begins. And that is not an easy thing to do, since the finest bulbous Oxalis species are only available suring a few weeks of the summer and only from a handful of catalogs, if that.

Carefully repotted summer dormant bulb species all lined up and waiting

My greatest mid-summer chore is repotting all of the bulbs which are now dormant in the summer. A great many of my collection does come from the southern hemisphere, and most of these transcend into a deep, summer rest, with some wanting to bake high on the sunner shelves of the greenhouse where they can remain bone dry, and others just want to get splashed occaisionally to keep their cell wall turgid, but not enough to ever signal that the fall rains have arrived. Late July is when I start repotting most of these winter bloomers, and this incudes collections of Cyclamen species, Narcissus from the Mediterranean and the bulbocodium type like N. romieuxii, N. cantabricus et al, Lachenalia, Romulea, and of course, the Bulbous Oxallis species, the jewels of the collection.

1. Carefully Remove dead foliage and topdressing.

Once Oxalis stop growth and whiter around May or June, allow the pots to go bone dry until you are ready to repot.Carefully remove old foliage and discard, being careful that no bulbs are attached to stems.

2. Dump compost carefully into sieve.
Be sure to selct a sieve with holes large enough to catch bulbs. Bulb size and shape differs greatly with species. I dump the entire pot into the sieve and then depending on the species, wither remove bulbs as I see them since many migrate to the bottom of the pot and are easier to remove before crushing the root ball, or with less robust species, carefully breaking the rootball to see if bulbs have divided at all.

Many Oxalis speces send bulblets down into the ground deep, so they line up against the bottom of the pot. One theory is that these bulbs remain dormant for years. Mother Natures back up system perhaps, in case a population burns or gets eaten by baboons I am guessing.

Removing these bulbs allows you to grow your collection, which is a good thing since on a whole, thes are not innexpensive bulbs since they sell for about $3.00 - $4.00 each and one must pot at least a dozen or more to get a nice display. You will want to propagate them this way since they do not produce viable seed.

3. Sift and clean.
Carefully pick out the bulbs, which is sometimes easy and at other times a challenge since some bulbs look exactly like rocks. This is also the fun part since you can see if you either lost a collection or grew is. Some species multiply well, while others remain about the same. It's a bit like digging for potatoes.

4. Store dry until repotting in early August.

Since I am repotting a day or two later, I am using platic zip-lock bags which I keep open, I would not suggest this, they we're just handy. Some may want to catalog or keep a spread sheet on bulb count, and I have done this for some species but not yet for Oxalis, I just don't have the time, but memory does tell me that some species that I ordered from Telos last year have multiplied well. I usually order 6 bulbs and all of last years pots have grown to about 30 bulbs, of various sizes. I save even the tiniest ones, so blooming size bulbs surely are at a minimum. I think I will repot some smaller bulbs in propagation pans so that they will have mroe room to grow and pick out the larger bulbs for show pots.

Uncommon South African bulbous Oxalis in bloom in the cold greenhouse in November

Watering for all of these dormant bulbs will commence with the first arctic cold front sometime in early September. The theory here is that not only do the fall rains trigger growing but also the temperature shift. I have watered as early as Labor Day, around Sept 1, and as late as Oct. 1.

Summer repotting will continue, starting here with Oxalis since they seem to send hair-like roots first, then Cyclamen species which have a very brief dormancy if at all. I then continue with the Narcissus, the followed by the balance of the minor South African bulbs with the ultilate goal of everything repotted dry and resting on the benches by the second week in August.

The Amaryllids like my collection of Nerine sarniensis are not repotted per say, just top dressed since thier roots do not go dormant, and the bulbs are, in fact, actually growing a bit during thier summer break of foliage. These also are getting an occaisional spritz of water.

Summer dormant Bulbs can only be shipped in August, so order now for winter bloom.
This is also the time to order bulbs that will bloom in the winter. If you have a cool greenhouse that remains frost free and cold, or anyplace that is bright, sunny and frost free, the winter growing bulbs from South Africa are some of the best performers and relatively easy once you master the cycle of winter wet and summer dry. For me, in the North East, this is easy with a glass greenhouse that is kept at 45 deg. F in the winter and allowed to get hot in the summer.

July 5, 2006

Perennials from seed - do the math

Primula "Wanda" blue from seed

Even though I should have repotted these seedlings earlier, growing Primorses from seed is by far the most economical way to start a collection, and since many of the species and crosses are hard to find in the trade, especially in any quantity, the benefits of sacraficing a few hours is well worth it.

First, do the math. These seedlings of Primula Wanda 'blue strain" are sold only at a fe mail order catalogs, ranging from $8.00 to $12.00 a single plant, then factor in the shipping cost at around %20 and the small window in which they can be shipped (early spring or after September, you can clearly see how a $12.00 packet of seed can be so cost effective when you end up with over 120 plants, which will bloom in thier second year.

The seed may seem costly at first, but that is because I not only by seed from the North American Rock Garden Society seed exchange (NARGS) and the American Primula Society seed echange (APS), where packets are free or only a dollar or so, I also buy pre-chilled seed from commercial suppliers, like Jelitto in Germany. A twelve dollar packet of thier pre-treated perennial seed ranges from $4.00 to 12.00 for more unusual varieties, but if you are interested in getting near 90% germination and don;t wish to fuss with freezing the posts and chilling hte seed to stratify, they have done the work for you.
I grow seed from all types of sources, but I still order some prechilled seed from Jelitto every year, for things like Rodgersia, Trycyrtis, Campanual and more, basically, those varieties that I would like to plant in larger numbers, but that I feel are too costly at $12-$18. per plant at a nursery. If you have ever visited Kew Gardens in ENgland, you can see how effective 18 to 30 plants of each perennial is when planted in an area. In fact, that is the only way to plant when you want a garden to look like a real English border, or like the cover of a White Flower Farm catalog. It's simply a fact of Math. I see so many peopl buying one to three plants of something like Echinacea, when they should be planting a clump of at least 15 pots to get a display that looks right.

Now you could easily end up with a surplus of Rodgersia, which isn't a bad thing at all!
NExt spring, try ordering pre-chilled seed from Jelitto, and by Autumn, you could be planting out hundreds of plants that you could otherwise never afford to plant in drifts.

April 21, 2006

Pleaching Hornbeams

This week I pruned the pleached Hornbeam hedge along the stone walk that leads out to the woods behind the house. I also decided to plant a new Pleached hedge of Hornbeams (Carpinus) along a new herb garden that I am planting on a very messy side of the house, since a huge 200 foot long Hemlock Hedge (Tsuga canadensis) that has been providing privacy in our yard since my grandfather planted it nearly a hundred years ago, is weakening and soon will be gone, due to an infestation of the Woolly Adelgid.

Pleaching is a ancient method of weaving branches to produce a hedge, often with the trunks showing. This French method is time and labor intensive, something that should make me reconsider the project, but on the other hand, it makes it seem even more attractive. Pleaching comes from the work Plechier, to weave, and one must use a tree species with flexible branches. Hornbeams are traditionally used, but one may also use Beeches.

The new planting will take at least five years before it starts to look good, but the bamboo structure helps to make the area seem less ugly.

April 5, 2006

Propagating Lachenalia

Lachenalia culture
Pollinate Lachenalia with a soft paint brush, just a gentle swipe with mimic a sun bird or a honey bee.

Many gardeners who keep a cool greenhouse are familiar with Lachenalia or Cape Hyacinths. Strangely enough, even though you may have never heard of this plant, some of my gardening books from the early 19th Century list dozens of species which were imported for cold greenhouse culture. Ridiculously easy, perhaps even for the cool windowsill or unheated room, the genus remains difficult to find for most gardeners. few nurseries sell bulbs, which leaves seed as the primary source for home collectors.

When bulbs are available, these are easy plants to propagate as Lachenalia can be propagated in a number of ways. First, you can pollinate your own plants ( the seed is easy to grow - relax, I know this all sounds so impossible!), but even better, if you can obtain a few bulbs for your winter garden ( yes, these are winter growers under glass), Lachenalia can be propagated by a strange, forgotten method which you may have not seen before - leaf cuttings. Leaf segments will produce bulblets in just a couple of months. Pretty cool, right?

Simple crosses can be made between species as well as within cultivars, but I prefer to keep my species pure, which is easier in the winter ( unless the greenhouse vents open and bees enter the greenhouse, but to be honest, I am not certain that lachenalia are insect pollinated, as most of these smaller South African bulbs are bird or even desert rat pollinated. Use a small camel hair watercolor brush, and you know the method - think back to your high school biology class. Simply sweep the brush across the stamens, being sure to get pollen onto the stigma. Some species produce a tiny cloud of pollen, which can drop out of the blossom when touched with the brush. Use this as a test, as the time of day is important - the winter  mornings can be damp and cold in the greenhouse.  Be sure to wait for a sunny day, so that all the sexy bits are dry enough.  Naturally, a clean brush is essential.

Raising lachenalia from seed
Lachenalia seed pods when ripe. The seed is large and easy to remove.

Seeds will form by June, and shortly after the pods will split. Different species produce different capsules. When you must collect seed at this point, check the capsule daily to watch for splitting, being careful to get them before they drop (if they do, just don't repot for a season. I have some pots full of seedlings, even though I thought I had collected all of the seed. Since Lachenalia are summer dormant in the Northern Hemisphere, (but our Australian friends are probably just getting their season under way) they must be kept dry all summer after the plant goes dormant, and watering started again in September. The same holds for seeds. I just store them in an envelope or sow them in dry medium, and start watering them in September. I plant the seed very deep in the pot, perhaps 2 or 3 inches down, which I started after seeing that the young seedlings eventually pull themselves down to the bottom of the pots, via contractile roots, and the bulbs lengthen to adjust. By planting deeply, I can save a year or two presumable saving some energy that the little geophytes were wasting in their attempt to relocate to a more favorable latitude, and thus, I now get flowers after three years instead of five. But wait...there is an even faster way to get bulbs...Leaf cuttings.

Propagating Lachenalia
Lachenalia leaf cuttings roots in a mixture of sand and Perlite. Leaf cuttings will produce small bulblets in a few weeks.

Raising Lachenalia from leaf cuttings

The leaf cutting method is by far, the easiest way to propagate many Lachenalia species, particularly the larger and showier Lachenalia aloides selections. Lachenalia generally produce only a pair leaves, so the only downside is that one leaf per plant can be harvested. Cut one leaf with a sterile razor blade or knife and cut it into three pieces, marking the bottom end with a marker, as this is the only end that will root and produce bulblets. Dip the bottom end into rooting gel, and place it in to a flat of fast draining yet moist, perlite and sharp sand.

Place the pan into a bottom heated propagating case, and within a couple of months, a few bulbils will grow from the bottom of each cutting . The disticial leave closest to the center of the plant produces the most bulbs, confirmed by research in Holland, so I only cut into three pieces now instead of five or six, as I once used to. Leaves rooted in January, will produce a dozen or more small bulbs by the end of that first growing season. These bulbs reach blooming size much faster, I have had L. aloides ssp. quadricolor bloom in the second year, so this seems to be the far faster way, and seeds are the best way if you want many bulbs, and one can't really have too many Lachenalia, can they!