Richard Bogren, Gill, Daniel J. | 8/31/2009 8:02:49 PM
For Release On Or After 09/11/09
By Dan Gill
LSU AgCenter Horticulturist
Gardeners use the term “volunteer” for the seedling of a desirable plant that appears in a garden without having been planted. They can be the offspring of trees and shrubs, but most often they are the result of seeds dropped by annuals or perennials previously grown in the garden.
Volunteers are nature’s gifts. You don’t have to pay for them, and they generally thrive where they are growing. They can be a welcome and wonderfully unpredictable part of an active garden.
One of the tricks of using volunteers in your garden is the ability to distinguish the seedlings or young plants of desirable ornamentals from unwanted weeds. Some books on growing plants from seeds include pictures of what the seedlings look like. You also can become familiar with the seedling stage of many annuals and perennials by growing them from seed yourself and observing them closely.
Keep in mind that any plant growing where it is unwanted can be considered a weed. Even volunteers of the colorful, fragrant four o’clock may be weeds if they grow in the middle of your rose garden or if you have too many. Live oak seedlings come up all the time, but you don’t want them growing in your flowerbeds. The art of using volunteers is not simply to allow every volunteer that pops up to grow. You must take into account the space needs of other plants growing in the area, flower colors, plant heights and the overall design of the garden.
On the other hand, volunteers can offer unimagined combinations. Using volunteers can add an element of surprise and a delightful, informal look to the garden. Sometimes these chance combinations turn out more beautiful than anything that you had planned. In my garden, the chance appearance of Kingwood Gold jewels of opar with its large, oval, chartreuse leaves among a planting of yellow columbines and blue forget-me-nots created a far more beautiful combination than I had originally planned.
If you want to encourage volunteers in your garden, you must allow seeds to form and mature on the plants you want to allow to self-seed. Keep old flowers picked off early in the season to keep your plants attractive and encourage more flowers. But toward the end of the season, allow the flowers to go to seed and let the seeds mature. Then, either harvest the seeds and scatter them around or simply let nature take its course and allow them to fall where they will.
Two other factors will affect the number of volunteers you see in your garden – Your efforts to control weeds also will prevent volunteer seeds from germinating. And the use of mulches and herbicides can limit or eliminate volunteers. Although I rarely use herbicides in my garden beds, I do mulch. Even so, I still see determined volunteers coming up here and there every year.
Not all garden plants produce viable seeds, and of those that do, many just don’t come up well under garden conditions. But many others are very adept at producing new generations in the garden. Even if you put in your garden a plant that reliably self-seeds, things still may not work out. Sometimes a plant that self-seeds with abandon in one gardener’s beds self-seeds little or not at all in another garden under similar conditions. Such is life.
Garden volunteers come up in the most unexpected places – in cracks in pavements, in flower pots and along the edges of beds are some typical spots – and it’s often necessary to either pull them out or transplant them to a more desirable location. If moved when very young, most volunteers can be transplanted with great success. You can even put them into small pots or cell packs filled with potting soil, grow them until they are larger and then plant them into the garden where you want them to grow.
The following lists include some plants I have found to be reliable self-seeders in our area – and there are many more. The warm-season growers should be planted next spring. Plant the cool-season plants in October or November. Also, check with your gardening friends. They often will have extras of plants that self-seed and would be happy to share them with you.
Abelmoschus, amaranthus, ornamental peppers, periwinkle, celosia, cleome, cosmos, balsam, marigolds, impatiens, salvia coccinea, purslane, torenia, melampodium, rudbeckia, Mexican heather, jewels of opar, four o'clock, asparagus ferns, knotweed, cypress vine, moonflower vine, cardinal vine, true ferns, basil, chocolate plant, garlic chives, perilla, ruellia, Dahlberg daisy.
Larkspur, sweet alyssum, nasturtium, cornflower (bachelor buttons), poppy, johnny-jump-up, dill, borage, coriander, parsley, viola, annual phlox, sweet pea.