How To Multiply Your Chrysanthemums
Most of the chrysanthemums blooming in gardens this fall will go dormant when the weather turns cold, then resume growing in spring. But some won't make it, even though mums are supposed to be hardy perennials. Inadequate snow cover, extreme cold, heaved roots and the absence of a thick organic mulch all contribute to their demise. Dormant mums mulched with 4 to 6 inches of chopped leaves or straw are most likely to live through most winters.
A quick way to divide a year-old mum clump is to look down at it and imagine it's a big pie, then use a sharp shovel to cut the mum pie in half vertically and horizontally. Next, cut each of the quarters in half, winding up with 8 chunks. Dig up each of these sections and plant them elsewhere in the garden in a hole enriched with compost. Snip out at soil level any hard, woody stems and all but 4 to 5 of the young succulent stems. Then tamp down the soil, and water.
Another way to divide an existing clump is to insert a shovel to its full depth into the soil around two sides of the plant, make a third insertion on another side, angling it to get under the rootball, then lift the whole clump up and out of the hole. Loosen the soil around the roots with a trowel.'
On the outer rim of the rootball you'll notice lots of new shoots with small, young hair roots, snip these rooted stems from the mother plant and place them in water for later planting. Because of the large number of young rooted stems that can be taken from the periphery of a year-old mum clump, you don't even need to bother with any of the woody center portion. Compost it instead.
To get even more plants, take 4 to 5 inch cuttings from the rooted stems or from undivided clumps still in the garden. Remove the two lowest leaves, make a .45° cut with a razor on the bottom of the stems, dip the stem in rooting hormone, and insert it in moistened vermiculite in shallow flowerpots, the type used for forcing spring bulbs is excellent.
When a rooted cutting is planted in May it's hard for a novice to visulize how much space the mature plant will require by fall. Planting rooted cuttings 25 inches apart seems like a tremendous waste of space. Yet a mum in flower needs at least that much room, and some of the large flowered varieties required even more. When I line out cuttings I plant them close, about 7 inches apart. But the close spacing is temporary. About a month after planting, every other seedling is transplanted to another part of the garden. or potted.
A few weeks later half the remaining mums are again separated, providing a full 25 inches between plants.
Pinching makes chrysanthemums compact and bushy. Pinching is just another name for pruning with your fingers, removing about an inch of stem per pinch. Start pinching the tips of rooted cuttings when they reach 6 inches. They'll develop additional stems from the leaf nodes below the pinch. When the new stems are 6 inches long, pinch those tips and the plants will produce more stems from the leaf nodes. By late July when pinching should stop the single stem, rooted cutting planted back in May will have developed into
a bushy compact plant with hundreds of stems with buds forming on their tips.
With organic fertilizer, compost and abundant water, chrysanthemums, even
the so-called low growers, tend to get top heavy. It's disappointing to nurture the plants from their infancy to maturity, have them come into full bud, then see them topple over from the sheer weight of the blooms. Add some wind and a driving rain and your prize mums will be flat on the ground. To preclude floppy chrysanthemums, I support the taller ones with twigs pruned from my fruit trees inserted in the ground around the plants when they're half grown. as the mums continue to leaf out during the summer their foliage soon hides the branches.
I enjoy mums for their attractive foliage from May to fall, then throughout bloom from September until frost. In pots both in and out of the house they become movable fall gardens.
Indoors or out, mums gloriously mark the conclusion of the gardening year.
They're the flower garden's last hurrah!
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