By Lesley Arrandale
I decided recently to grow more of my plants from seed. I’m not an expert, but I can see there can be advantages in growing flowers with some genetic variability. In contrast, flowers grown from cuttings — vegetatively propagated clones — will be just like the parent plant and have the same strengths and weaknesses.
Open pollinated seeds, however, will produce subtly different plants, since the genes that make them more or less drought tolerant, perfumed, larger or smaller flowered are unique to each seed and thence to each plant.
Hygiene is important. Before reusing seed trays and pots, wash them in warm soapy water, and rinse them clean. To kill any harmful organisms, give them a final rinse in a bleach solution of one part bleach to nine parts water, and let them air dry. There are plenty of alternative seed-starting options available, such as plug trays, peat pots and expanding peat plugs, which can be convenient. Always use a good quality seed starting compost formulated for germinating seeds, rather than regular potting soil. If you buy seeds, follow the advice on the packet for when to sow, and how deep to sow them. Generally, tiny seeds should barely be covered, and others should be buried one to one-and-a-half times deeper than their diameter.
If you decide to collect seeds from your own garden, make sure to collect them when ripe, which is usually when the seed heads are brown. Some seeds are shed very easily from the plant, so be watchful. Separate seeds from the rest of the flower head, allow to dry, and store in a sealed envelope in a cool dry place. For longer shelf life, seal the envelope in a plastic bag and refrigerate. If you have a reliably hardy perennial you want to propagate, you may want to get a jump on next year’s growing season, and simply collect your seeds and start them the same year. Just don’t collect seeds from hybrid plants, as they won’t give you reliable results.
If you are growing seeds indoors, give them bright light once they are up, not too much water, and begin using a dilute liquid fertilizer once a week. When the roots fill their containers, move the plants into four-inch pots, teasing apart any circling roots. Keep the potting soil fairly light and fluffy; don’t pack it down hard. Don’t thrust your seedlings into bright sunlight for the whole day, even if they will need it when in the landscape. You will have to baby them until they are hardened off, introducing them to full sun only gradually, and you may need to move them up into larger pots to develop a larger, stronger root system before planting out in your garden bed.
Seedlings started outdoors in the ground or in a greenhouse will be accustomed to full sun. You will need to pay close attention to watering to ensure they don’t dry out while germinating.
Shrubs can be slow to grow from seed, so you may decide to take cuttings of your favorites. For more information, see “Plant Propagation Techniques for the Florida Gardener” (http://edis.ifas.ufl.edu/mg108).
In the vegetable garden, okra, sweet potatoes, hot peppers, lima beans and southern peas, and basil are some crops that should be doing well during the depths of summer. If so, fertilize them regularly according to the product packaging and enjoy your bounty. Daily scouting for pests will pay dividends, in that you will be in charge, not the insects.
For some relief from the summer heat, why not take time to reflect on your plans for the fall, and particularly if a new tree features in them, use these torrid days to plan the right plant for the right place. Happy summer.
Lesley Arrandale is a Master Gardener with the Duval County Cooperative Extension Service/City of Jacksonville Agriculture Department, which is a partnership between the United State Department of Agriculture (USDA), the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) and the City of Jacksonville.