‘Volunteers’ Aren’t Always Welcome
Every year you should expect some volunteers in your garden. But don’t start watching for carloads of helpers to pull into your driveway. The volunteers to which I am referring are plants, not people.
“Volunteer” plants are annuals that regrow every year by themselves, saving you the trouble of planting them.
And where do these volunteers come from? Most originate from seeds ripened and dropped on the soil in fall and winter. The herbs dill and borage are notorious for this habit--plant them just once and never again.
Garlic chives are tasty and attractive, but be careful: They can easily overtake a spot of garden. They self-seed prolifically and are hard to weed because of their slippery, strap-like leaves.
Annual flowers that self-sow include alyssum, calendula, cornflower, cleome, cosmos, California poppy, morning glory, petunia, nicotiana and moss rose.
You will probably find self-sowing seedlings of any of these plants coming up this year, usually near where they grew last year.
Other volunteers come from the compost pile. You might unknowingly spread seeds when you spread compost over your garden. The heat of composting can destroy many seeds--thankfully, because otherwise the garden would be overrun with unwanted plants.
But not all compost piles heat thoroughly or adequately. And anyway, tomatoes can tolerate the heat of composting and often appear even where well-cooked compost is spread.
Sunflower, melon, squash and pumpkin seeds are large enough to be able to burst forth from a cool compost pile’s innards, or grow wherever the compost is spread. Occasionally, these plants will appear where an overlooked fruit rotted on the ground the previous season.
To encourage volunteers such as tomatoes, sunflowers and dill, don’t be overly meticulous in gardening. If you harvest all the dill when it’s young and green, there will be no plants left to sow seeds.
Covering the whole garden with a 3-inch blanket of leaf mulch often means that small-seeded volunteers will use up their energy reserves before the seedlings reach light. Over-meticulous weeding is another habit that eliminates some potentially valuable volunteers.
On the other hand, you cannot give volunteers free rein. A weed has been defined as “a plant out of place,” and there is a fine line between a welcome volunteer and an unwelcome trespasser. An exuberant pumpkin vine is out of place in a bed of carrots. If 25 tomato plants pop up in a couple of square feet of space, most are--almost by definition--weeds.
