Tutorial: Propagating chrysanthemums from cuttings

In late June, I cut back my chrysanthemums to make sure they’re compact and full of buds when flowering time comes in September and October. You can root the pieces you cut back from your own plants, and have dozens more plants the following year. It’s very easy to do.

Rooting cuttings of chrysanthemums:

1. Cut back the stems of your chrysanthemum plants by about half, cutting just above a leaf node (where the leaves join the stem).

2. Separate the stems. Cuttings should include between 3 and 6 leaf nodes. Remove the growing tips to force the plant’s energy into making a vigorous root ball. Then remove the leaves from the bottom half to 1/3 of the stem.

3. Pour a small amount of rooting hormone into a container. Don’t dip stems directly into the container, which could contaminate the entire jar. Thoroughly coat the cut end of the stems with hormone.

4. Use a chopstick, pencil, or other tool to make a hole for the cutting in a pan of sterile potting mix. Insert the cutting into the hole, and firm back around the cutting. Water the cuttings gently, using a rose attachment on a watering can, a light setting on a hose nozzle, or a fine mist from a sink sprayer.

5. I keep my cuttings outside, weather permitting (i.e., it’s not freezing). I put them in a shady spot, like a north-facing wall, where they can get rainfall but not direct sun. Keep the tray watered if the weather is dry; do not allow the mix to dry out entirely.

6. Your cuttings will be ready when a gentle tug on the leaves gives resistance. If the cutting doesn’t come out easily, it has formed a good root mass. In early summer, the process takes me about one month. You can then transplant the cuttings into the garden. Keep them pinched back and watered, and you’ll have abundant flowers in fall.

 

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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.

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

Seed saving 101: Cucurbits

To continue with the seed-saving series, let’s focus on cucurbits (melons, squash, cucumbers). As with corn, the seed-saving challenge for the home sub/urban gardener will be to maintain a population size that will permit seasonal attrition and genetic diversity.

Common name

Scientific name

Variety name

Isolation distance

Population size

Pollinators

Melons, cantaloupe Cucumis melo ‘Minnesota Midget’ 1600’ 10-20 Insects

Know what you grow.

When it comes to cucurbits, the gardener must know the scientific names of the crops she wants to grow. Cucurbits will cross-pollinate within their species (Cucumis melo with other Cucumis melo) but not inter-species, i.e., within the genus. So you can grow ‘Minnesota Midget’ cantaloupe next to your zucchini (Cucurbita pepo), and they’ll be fine. But you cannot grow cantaloupes, honeydew melons, and crenshaws together (all Cucumis melo) without expecting cross-pollination.

Common names in this family can be misleading. Armenian cucumbers, for example, are Cucumis melo, but regular salad-type cucumbers are Cucumis sativus. Summer squash, another cucurbit, is Cucurbita pepo, as are pumpkins, but winter squash may be Cucurbita pepo (acorn, crookneck, scallop-type, and spaghetti squash; zucchini; and pumpkins) Cucurbita maxima (hubbard and turban squash, buttercup squash, and some pumpkins), Cucurbita moschata (butternut squash), or Cucurbita argyrosperma.

In short, if the Latin name is the same, you can’t grow them together without cross-pollination. If the first half of the name is the same but the second half isn’t (Cucurbita pepo and Cucurbita moschata), you’ll be fine.

Getting them growing

First, keep cantaloupes and other muskmelons 1600 feet away from other muskmelons (what’s your neighbor growing over his fence?).

Cucurbits are insect-pollinated, and given the distressing decline in native pollinator populations, it’s not fair to assume you’ll have a healthy supply of wild pollinators nearby. Without an abundance of natural pollinators, you may have to resort to hand-pollination to get any fruit set. Fortunately, hand-pollinating is quite simple.

Cucurbits produce male and female flowers on the same plant. Fruit will form from the female flowers if they are pollinated. Female flowers can be distinguished from male flowers by the fruit (the bulbous part, or ovary) at the base of the flower. Male flowers do not have an ovary.

To hand-pollinate your plant, pick a male flower from the plant and peel back its petals, exposing the pollen on the anthers. Find a female flower, and gently open its petals if necessary.  Rub the pollen on the stigma, and let the petals fall back to their original position. One male flower can pollinate multiple female flowers.

Male acorn squash flower (Cucurbita pepo) by Forest and Kim Starr [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons

Female acorn squash flower (Cucurbita pepo) showing large, dark-yellow stigma. By Forest and Kim Starr [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

Female acorn squash flower (Cucurbita pepo) showing large, dark-yellow stigma. By Forest and Kim Starr [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons

Pollinating the female stigma with the male anther. Photo by Jay at Scientific Gardener under Creative Commons 3.0.

Pollinating the female stigma with the male anther. Photo by Jay at Scientific Gardener under Creative Commons 3.0.

The flowers tend to open early in the morning, and close as the heat of the day increases, so plan your pollination activity accordingly. A peculiar habit of cucurbits is that the female flowers often develop later in the season than the male flowers. Day length, light intensity, and temperature all influence the ratio of male to female flowers produced. Long, hot days yield more male flowers; cooler temperatures and shorter days yield more female flowers.

Saving the seed:

Muskmelons are easy. When the melon is ready to eat, the seed is ripe. Separate the seeds from the flesh, rinse them clean, and allow them to dry on a screen away from heat and direct light. Store in a clean glass jar or paper envelope in a cool, dry place.

Seed saving 101: Understanding isolation distances

In order to save seed and, more to the point, be a good steward of the health and success of open-pollinated varieties, it’s important to take a few precautions.

Perhaps the most challenging one, particularly for (sub)urban gardeners, is that of observing some isolation distances. Isolating plants is a way of preventing the pollen of two closely related varieties from mixing, thus ensuring a relatively stable and pure strain of seed.

A pure strain of seed? Didn’t we want genetic diversity? Well, yes, but not too much. There is a balance to be struck: We want enough diversity to maintain a healthy and well adapted variety, but not so much that the heirloom cabbage you love doesn’t resemble that same cabbage anymore. Seed saving and seed stewardship are a blend of art and science, but don’t be terrified or put off by that. You alone will not irrevocably destroy your favorite variety of cabbage.

Of course, if your whole ambition is to produce a totally different variety by throwing everything into the pot and seeing what comes out, plant with abandon, but please don’t share your resulting seed and promise it’s going to be the original. And be considerate of your neighbors, and any plans they may have for their own gardens.

First steps in planning your summer gardening and seed-saving activities:

  1. Assess your site. Understand the space you have available to grow your crops and the light the site receives.
  2. Identify the crops you want to grow.
  3. Learn your plants’ scientific names, and which other plants share that scientific name. That means both parts of the name: the genus and the species (not the part in single quotation marks). It’s especially important if you wish to grow cucurbits (squash, cucumbers, melons, pumpkins) or brassicas (broccoli, cauliflower, cabbage, collards, kale, to name a few).
  4. Depending on the size of your property and your proximity to your neighbors (especially critical if you grow in a community garden), learn:
    1. What your neighbors’ plans are for their summer gardens, if any.
    2. Whether anyone in your vicinity is a beekeeper.

The topic is a big one to grasp (bigger than I realized when I set out to research the issue), so I’ll break down an example in my next post.

Germination!

My home office is carpeted with seed flats of various origins. What’s sprouting today?

Red-foliated white cotton seedlings

Red-foliated white cotton seedlings