More of a good thing: Propagating trilliums and other rhizomatous plants

My favorite time of the gardening year is when my trilliums come into bloom.

Trillium luteum

Trillium luteum

These plants, native (in the case of Trillium luteum) to North Carolina, grow in deciduous forests. Slow-growing and typically reproduced by tissue culture, they command hefty prices at nurseries and garden centers, in the range of $15-20 for a quart pot containing one plant. Please don’t use this as an excuse to harvest them from their native habitat; that’s strictly taboo.

I have been waiting patiently for perhaps eight years for these plants to multiply. This year, I think the oldest of my three plants may send up a second bloom. Growing trilliums is a bit like watching children mature, I suppose; the gardener must exercise a great deal of patience as the subject slowly and rather invisibly matures, showing exciting glimpses in brief bursts of what lovely and graceful specimens they will become.

Well, my patience is not where it ought to be. You can imagine my excitement, then, when I read in Nancy Goodwin’s delightful book, Montrose: Life in a Garden, about how she increased her stand of Trillium catesbaei by pricking the rhizomes with a pin to stimulate new growth.  She describes a ninefold increase in her plants in one year using this technique.

I contacted Nancy to ask about the process and she assured me it was extremely simple. Uncover the rhizome (easiest to do now, when the flower is visible), and prick it with a pin beneath the growing point, found at the end of the rhizome. The injury stimulates the plant to produce additional tubers, she writes. Perhaps while the plant photosynthesizes, it pumps more energy into additional tuber/rhizome (I will grasp this one day) formation, yielding a greater increase than would occur if, say, the gardener tried this technique during the plant’s dormancy.

Yesterday I gave it a try. I dug gently down with my fingers, not wanting to risk severing the rhizome with a vigorous plunge of a trowel (perhaps an irrational thought, given what I was about to do). I found the growing point, or what I think is the growing point, and, not having a pin to hand, gave it a timid poke with the tip of a pair of scissors. I made an incision only detectible by the droplet of white fluid that emerged from the rhizome. I filled the hole back up and firmed it well. I tried the technique on two of the three plants, so if I’ve erred in my execution, next year I can be assured of having at least one plant surviving (the one that’s sending up two flowers this year).

Feeling a bit bold, I tried it on the single specimen I have of Trillium sessile as well.

Trillium sessile (red)

Trillium sessile, dusted with pollen

Next year, we’ll see what emerges. You may want to give this technique a try in your own gardens. If you do, please let me know your results.

Garden log, 4.14.14

After four or five days near 80 degrees (26C), everything in the garden has exploded. The daffodils, which like a long, cool spring, expired in the pseudosummer of last week. Pollen rains down constantly and blows in great clouds, like photos from the Dust Bowl, except yellowish green. The weather report calls for lots of rain tomorrow, and perhaps a freeze tomorrow night. I must dig out the plastic sheeting to protect the tomatoes I spent last week planting.

But iris season is coming. My first blossom of ‘Eco Easter’ appeared today. Flora Weather, I hope yours are just as pretty! Enjoy them.

Iris 'Eco Easter'

First dates: Gilia tricolor

Second in the series “First Dates: Plants I’m Trying This Year”

Gilia tricolor is an annual plant native to central California. Bees (and I) love the small, open-faced flowers.

Gilia tricolor

Gilia tricolor. Photo courtesy of Annie’s Annuals.

I have read that they like moist soil, and I have read that they like dry soil. I’ve read they like hot conditions, and that they prefer cool summers. At $2.25 per seed pack, I figured I could experiment and see who’s correct. It’s entirely possible that they all are.

The cultivar I am growing, ‘Felicitas,’ offers half-inch pale pinkish-purple blossoms brushed with darker red-violet tones in the throat of the blossom, and a sharp yellow color in the cup. The anthers hold faint blue pollen above the blossom, which makes for a charming, offbeat color contrast (should it be called Gilia quadricolor?). The plant self-sows where it is happy. This, like the Mina lobata profiled yesterday and several of the other plants I’ll showcase later this week, are open-pollinated annuals. That means that while they’ll live their life cycle in one year (growing, flowering, setting seed, and dying), their offspring will perform the same show the following year. Thus, although the plants themselves are not the same, the result in the garden is much like that of having perennials (those plants which do come back year after year).

‘Felicitas,’ seems to be on the smaller side, growing 12 inches tall and wide, whereas others grow slightly larger, 18-20 inches tall and perhaps 12-18 inches wide. The flowers apparently smell faintly of chocolate, and what they lack in size they make up for in abundance. The leaves are fine and needle-like. A member of the Phlox family (Polemoniaceae), they can be found in Yosemite National Park.

Gilia tricolor 'Felicitas'

Gilia tricolor ‘Felicitas.’ Photo courtesy of Select Seeds.

They are supposed to make fine cut flowers.

I hope to grow these in the blue slope, a patch of west-facing land close to the radiant heat of the street. The plants that live out there need to be tough, and these seem to fit the qualifications.

 

First dates: Plants I’m trying this year

This week, I will share some of the plants I’m trying out in my garden for the first time.

Mina lobata

Mina lobata uses numerous aliases, including firecracker vine, Spanish flag, and exotic love vine. This sun-loving annual grows quickly to 10 feet long and produces lush, trilobed leaves similar to those of Ipomoea batatas, the sweet potato vine, to which it is related. In late summer to early fall, Mina lobata produces red flowers that fade to orange, yellow, and white. Those tubular (as in tube-shaped, not as in surfer-speak) flowers attract swarms of hungry hummingbirds, so plant it where you can enjoy the show. The vine will reseed to come back year after year, but do be mindful that the seeds are poisonous so keep them away from children and pets.

Mina lobata

By Magnus Manske (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons

Synonymous with Ipomoea lobata, this plant is related to morning glories and I expect similar habits. I’ve not had much trouble with reseeding morning glories, but I keep an eye out so nothing gets out of hand.  Mina lobata is said to cope well with heat and humidity, which I can guarantee in my neighborhood.

I thought I first saw this plant growing at Montrose last fall, combined with Helianthus, cosmos, and other fiery flora. But upon closer inspection, I’ve discovered that what I thought I was admiring was not Mina lobata, but Cuphea micropetalum.

Border at Montrose with Helianthus, Cuphea micropetalum, and orange cosmos.

Border at Montrose with Helianthus, Cuphea micropetalum, and orange cosmos.

This is what I thought was Mina lobata. It's not. It's Cuphea micropetalum.

This is what I thought was Mina lobata. It’s not. It’s Cuphea micropetalum.

To grow from seed:

Scarify the seed (scratch with sandpaper or nick the seed coat slightly) and soak in water overnight or up to 24 hours to improve germination. Sow seed outdoors after the last frost, or sow indoors and transplant after the frost risk has passed. Give its twining stems a trellis or tuteur to climb upon, or train it against a fence or wall you’d rather not see. Like clematis, its roots prefer some shade, and it likes rich soil, neutral to slightly acid pH, and moderate water. Do not overfeed Mina lobata with high-nitrogen fertilizer, or you will have lush vines and few flowers.

If left to dry on the vine, the seed heads may be harvested, cleaned, and stored in a cool, dry place.

 

Know thine enemy: Common weeds to know

Here’s a terrific chart of common weeds, by the Missouri Botanical Garden. Get to know the weeds that make their homes in your garden. The more you know about them, including their life cycles and reproductive habits, the more weapons you have with which to thwart them.

And please, avoid using chemical weed controls. They can be toxic to pollinators, including bees and butterflies, and can persist in the soil for very long periods of time. Mulch and other methods of weed control are more sustainable, and healthier for you, your family, your pets, and the environment over the long term.

 

Joe Pye weed, Eupatorium fistulosum