tough plants

Linaria purpurea flowers

My Tough Plants #1: Purple Toadflax (Linaria purpurea)

My garden, as I’ve said many times, is a 50-by-120-foot suburban lot with the usual house, driveway, garage and paved walks. Among those elements are half a dozen beds or borders containing combinations of shrubs, perennials, and self-sown annuals. There are also small areas of grass (sometimes called “the lawns,” although that sounds rather grand).

The soil is a light sandy loam, with good drainage. The climate is semi-Mediterranean, which means mild wet winters and dry summers. Recent summers have been drier and warmer than normal. Most of the plantings are affected to some extent by four large Norway maples, a big birch and a medium-sized Tree of Heaven (Ailanthus altissima).

In this difficult situation — dry, rooty shade — a few reliable tough plants perform quite well, because they are tough and almost weedy. Properly managed, they can be quite ornamental. I plan to write several posts this summer about how I use these plants in my garden.

First up is Purple Toadflax (Linaria purpurea). Apparently, the leaves resemble those of the flax plant, which explains the “flax” part of the common name and the “lin” (linum is Latin for “flax”) in the genus name. I’m not sure where the toad comes in.

The plant grows between 1 and 3 feet  (30 cm  to 1 metre) tall. In shade, it can reach 4 feet. It’s somewhat slender, so inserts itself easily among other plants without crowding. Most plants have between 4 and 10 stems. The stems are stiff and never need staking.

Linaria purpurea foliage and flowersThe individual flowers are like tiny snapdragons. They cluster in spiky racemes at the tops of the stems. The standard colour is medium to dark purple. I’ve had a few plants whose flowers are purple and white, but they’re rare. Pink flowers are more common than the bicolours. They’re a fairly pale pink, though; their main interest comes from being different from the norm. The standard purple is a fine colour, contrasting well with the grey-blue-green of the slender leaves.

Linaria purpurea flowers with bumblebeePurple toadflax is of no interest to deer. It grows well and blooms reliably in dry, rooty soil and shade. It thrives in sunny spots. Bumblebees love it.

What’s not to like? Well, I did say it’s a quasi-weed. Left to its own devices, it blooms in May and June. The flowers are succeeded by seed pods that look like tiny green beads. At this point flowering stops. Seeds ripen by summer’s end and scatter when the plants are disturbed. The following spring hundreds of seedlings emerge, producing more toadflaxes than anyone wants. An untended patch of toadflax is reminiscent of gravel parking lots, not garden borders.

Linaria purpurea fall foliageRigorous deadheading is the way to curb the plant’s weedy tendencies. Clip off the spikes of bead-like seed pods as soon as they form. You can either cut each thin side-stem or wait until the whole raceme has pretty much finished flowering and cut the main stem just beneath the flower cluster. The plant will put out new flowering side-stems and keep blooming all summer. A bonus of this process is that the foliage of plants growing in sunny spots turns interesting shades of pink in autumn.

The trick is to deadhead before the seeds ripen. Inevitably, a few plants escape my notice. I discover them when I’m doing fall cleanup, by which time the tiny seeds scatter far and wide. A desperation measure for this situation is to carefully clip the seed-bearing top of each stem and transfer it into a pail or similar container, preventing seed scatter. I suspect semi-ripened seeds are able to finish maturing in the compost pile, so it’s best not to compost them unless you’re sure your heap achieves temperatures high enough to kill seeds. Mine doesn’t.

This is why I know how well toadflax blends into plantings. I don’t remember ever actually planting it. I go through the beds in spring and remove excessive seedlings and badly-positioned plants.

Toadflax is a short-lived perennial. Individual plants persist for two or three seasons. Eventually, they get woody at the base and perform poorly. By that time, though, there are more than enough young plants to replace them.

I wouldn’t recommend purple toadflax for mass plantings. The skinny, diagonally placed leaves produce a visually tedious herringbone tweed effect. Besides, this mass planting effect is what you get when you let toadflax self-sow with abandon. I like them best among other plants with contrasting leaf shapes.

More info about Purple Toadflax is available at the Missouri Botanical Garden site and Wikipedia.

 

Advertisements

Thugs, Prima Donnas… and Mulleins

When I began making this garden in 1992, I didn’t have a lot to spend on the project, so I was happy to fill up the space with pass-along plants from other gardeners, waifs and strays of unknown provenance and tough, easy-to-grow self-seeders. Many of these are still with me, prospering despite the sandy, tree-root-infested soil and dry summers. I’ve written about them here already.

Like most gardeners, I’ve also wanted to grow more challenging plants — refined roses, delphiniums, oriental lilies and (the gardener’s supreme challenge), Himalayan blue poppies. For several years, I pored over the catalogues of a nursery located in the Fraser Valley, and every year brought home a selection of their offerings. I ordered seeds of carefully-researched perennials and successfully raised seedlings. Some of those acquisitions are still with me, and a few are doing well.

Geranium "Anne Folkard" and Clematis integrifolia

Geranium “Anne Folkard” and Clematis integrifolia

 

Dictamnus albus

Dictamnus albus

But. (There’s always a “but”).

My garden is now bursting full. If I want to try something new, something has to be removed. Quite a few of the purchased and grown-from-seed plants are long gone, remembered only from a sad collection of labels in my garden shed. Cosmos atrosanguineus, Gaura lindheimeri “Siskiyou Pink,” Lamium maculatum “White Nancy,” R.I.P. Farewell, Coreopsis verticillata “Moonbeam,” Trifolium repens “Dragon’s Blood” and Cimicifuga racemosa.

The good old tough plants are, of course, thriving. Hellebores, toadflax, rose campion, lamb’s ears, lady’s mantle, foxgloves, fireweed and a number of ferns. The fussy, “quality” plants, however, live in pots. No root competition and individual attention from the gardener in the form of fertilizer and water.

Potted Oriental Lily and Zeke the Cat

Potted Oriental Lily and Zeke the Cat

Pots aren’t foolproof, however. I bought this potted lily a week ago to replace two that gave up the ghost because I allowed self-seeded “hitchhiker” plants to take over their pots. Another threat is excessive winter wetness. A couple of my delphiniums perished from that, and it was literally death to my idea of growing blue poppies in pots. Better results may be possible if one ensured really good drainage and situated the pots in a spot out of the rain (and remembered to check for excessive dryness at times over the winter).

For the past three years, my blue poppies have had their own bed near a magnolia. Last year they bloomed; this year they decided to give it a miss, even though they look healthy. I am catering to them with mulches of compost and peat, extra fertilizer, regular watering and shade from afternoon sun. As in farming and hockey, maybe next year.

Tough plants need to be controlled and discouraged. Delicate beauties need to be cosseted and coaxed. Pots aren’t always a solution and there are no guarantees.

But mulleins look great most of the time. I have given over my former vegetable patch to herbs and mulleins — Verbascum olympicum and Verbascum chaixii. Even before they bloom, they look interesting.

Verbascum chaixii rosette from above

Verbascum chaixii rosette from above

Mulleins seem to know that anticipation is almost better than fulfillment. They take a long time to grow their bloom stalks and look great through the process.

Olympic mulleins, Verbascum olympicum

Olympic mulleins, Verbascum olympicum

In the end, I have to ignore the distinctions between tough plants, refined plants, purchased or self-seeded. Right now, the garden looks pretty good. Right now. That’s what counts.

May 31, 2014

 

 

Lessons Re-Learned

Epimedium "Frohnleiten"

Epimedium “Frohnleiten”

Today was my first full day of gardening since last fall (not counting the pruning session in March). While generally happy with things in my little plot, I was reminded of a few truths for those who garden in small spaces (anything less than half an acre).

1. Never plant any shrub that suckers, no matter what sentimental associations it may have, or that it’s a native plant, or that some garden writer you admire spoke highly of it. This includes Oregon grape (Mahonia aquifolium), snowberry (Symphoricarpos albus) and the common lilac (Syringa vulgaris). It also includes the woody perennial (not quite a shrub) Phygelius (also known as Cape figwort). I have all of these, and spend several unpleasant hours every year yanking, snipping and sawing their adventurous shoots. It’s an especially unrewarding task because I know most of the shoots will re-sprout and new ones will join them. It’s too late to remedy my unfortunate plant selection decisions, however, since the original shrubs, now huge and deeply rooted, would require immense labour or dynamite (or both) to dislodge them. Beware of rampaging groundcovers as well, such as ivy and Vinca major. Even the deceptively dainty-looking Vinca minor has thuggish tendencies.

2. If your garden looks like a hopeless mess at this time of the year, do three things before you give up on it:  mow the lawn, edge the beds and cut down last year’s old stalks. This will instantly impart the look of a managed garden and motivate you to make further improvements by weeding, loosening the soil, introducing new plants and mulching. Even if the plants occupying the beds are nothing special, this treatment will make them look better. (This applies to perennial and mixed ornamental beds; vegetable gardens are another thing altogether).

3. If your garden is mainly one of tough, drought- and tree-root-tolerant perennials and shrubs along with various bulbs, don’t expect plants with more exacting requirements to do well or even survive without a lot of special attention. They are already having to put up with less than ideal growing conditions and will be no match against tough, colonizing plants such as peach-leaf bellflower, lamb’s ears, toadflax and rose campion. If you can’t provide them with a separate bed, keep an eye out for their early spring growth and make sure they aren’t overwhelmed by their robust, faster-growing companions. I say this after rescuing Thalictrum delavayi “Hewitt’s Double” and even Geum chiloense “Mrs. Bradshaw” (which isn’t generally considered a delicate thing, but is treated like one in my rooty patch). As for my blue poppies (Meconopsis), they have their own slender slice of earth to dwell in, but I wonder if it’s too close to a rather hefty magnolia. They have sprouted out quite well, all seventeen of them, so I have hopes.

Henry Mitchell said, “The life so short, the craft so long to learn. This was said about literature, but it really fits gardening better.” Very true.

Fiddleheads of Dryopteris filix-mas

Fiddleheads of Dryopteris filix-mas

Bellflowers, Peach-Leaf and Others

My somewhat cranky post on Peach-leaf Bellflower has to be one of the most visited in this blog’s archive. It seems a lot of gardeners are interested in bellflowers. Because that post was a diatribe against Campanula persicifolia, I thought I would take a more temperate look at them now, when their first flush of bloom is nearly over.

Peachleaf Bellflower

Peachleaf Bellflower

The genus Campanula, or bellflowers, is huge — more than 500 species. It includes perennials, biennials and annuals ranging from a few inches high to six feet, but most seem to be in the one to three foot range. They occur in a variety of temperate habitats, including woodlands, grasslands, alpine and arctic regions. Dozens of species have found their way into gardens and have attracted the attention of plant breeders, resulting in many horticultural varieties.

I personally have experience with only a few of the bellflowers. Only two, actually. I recall the biennial Canterbury bells called “Cup and Saucer” from childhood, but have never grown it myself. Someone once gave me a plant of a creeping type, possibly a cultivar of C. carpatica, but it did not last. The two that have, and will probably be here forever, are C. persicifolia, Peach-leaf Bellflower, and C. rapunculoides, whose common name — Creeping Bellflower — should give any gardener the creeps. The authors of Perennials for American Gardens warn that “it must never be introduced into gardens, except into the wildest areas.” Well, it somehow got introduced into my garden, although not by me. At present, there is a clump growing out of asphalt on the edge of the driveway and another at the base of a Norway maple. The latter appears to be spreading slowly. Every spring I dig up the outermost sprouts, but I suspect it’s gaining ground. I also see it over the fence near my shed, and have conducted a little herbicidal warfare to keep it out.

The interesting thing is that the rapacious C. rapunculoides is quite attractive — more so than C. persicifolia, whose flowers are wide open, outward facing cups, while those of the former are downward-facing in the true bell-like manner, with elegant pointed edges.

Creeping Bellflower

Creeping Bellflower

On my way to work by bicycle I admire a nice clump of this plant growing at the foot of a bus stop sign, in the crack between sidewalk and curb. It’s obviously never watered except by rain (nonexistent at this time of year) or cared for in any way, but puts on a show every summer.

But — and it’s a big “but” — these two bellflowers are inveterate spreaders. Rapunculoides spreads mostly by underground rhizomes, forming fat tuberous storage roots. Every bit of root is capable of forming a new plant, so careful digging and disposal (not in the compost heap) is needed to remove it. Mostly it’s impossible to get rid of it entirely which is why it needs to be watched carefully and extracted as much as possible every spring.

Peach-leaf bellflower distributes itself both by seeds and underground roots, but is generally a bit easier to remove, except when it becomes entrenched among other desirable plants, when digging it up means digging up the entire bed. Careful deadheading can prevent excessive seeding, but the more plants you have the harder it is to keep up with the spent flowers about to become seedheads. The purest deadheading technique is to snip each flower individually, allowing the new buds forming lower on the stem to develop. This is fine if you have only a few easily accessible plants, and more time and patience than I have. Cutting entire flowering stems once most of the blooms are over works quite well. My plants manage to rebloom once or twice after this treatment.

So do I still think of Peach-leaf Bellflower as a “garden enemy?” Not really, but I suggest that gardeners think carefully before introducing it, especially to neat and tidy gardens. It’s actually one of the tough plants that are valuable in adverse conditions (such as dry shade), but become a little too pushy in favourable ones. In such situations, I would advise a gardener who wants to try campanulas to visit a good garden centre and obtain some of the horticultural named varieties, which tend to be less aggressive.

And for those who already have these two bellflowers, all I can say is that they create an opportunity for the gardener to exercise some mental discipline. Fight or negotiate? Attack or maintain a watchful peace? Who says gardening is a genteel pastime?