Cuttings sit in a cup of rooting hormone solution before being planted in perlite for seven to 10 days. (Joan Morris/Bay Area News Group)
Propagating plants, whether by seed or cutting, is a rewarding hobby that can become a way of life, says Kathy Echols, a grower and former horticultural instructor.
"It's cheaper than alcohol and drugs," Echols says, "but it's just as addictive."
Echols once taught propagation at Diablo Valley College in Pleasant Hill. Now, she runs a successful growing operation that supplies plants to a number of nurseries.
Echols spoke to Our Garden this week, demystifying propagation and encouraging gardeners to give it a try. Here are her best tips.
Growing by seeds Know what you're growing by doing a little research, Echols says. Reading the seed packets gives you basic information, but the instructions are general, written for everyone in the country. What's true for New England may not be true for California. Knowing where the plant originated can help, too. A plant with roots in the Mediterranean will likely need a dry climate, while plants that originated in tropical zones will probably require more water. Some seeds you can just plant and have success, but others require stratification -- roughing up either through cold, heat or abrasion. When starting seeds, use a sterile planting mix with a peat moss base. The general rule of planting seeds is to take the length of the seed, then multiply it two to the three times to get the depth it should be planted. For example, if you have a seed that is a half inch long, you would plant it 1-1½ inches deep. Very tiny seed can be dusted on top of the planting mix and watered in. If your seeds don't germinate, it may not be your fault. Keep track of how many you planted and how many germinated. Most seed companies guarantee 80 percent germination so if you don't get that, contact the company. Seeds don't need to be fertilized, but the seedlings will. Don't buy a variety of fertilizers, Echols says. Just get one where the amounts of nitrogen, phosphorus and potassium (or potash) are equal. For example, the numbers on the fertilizer could be 10-10-10 or 15-15-15. Liquid fertilizers are best for seedlings; easy to use and easy for the new plants to take in.
Seedlings Once your seedlings are large enough to transplant, use a damp potting soil and make sure the hole is large enough so the roots aren't disturbed, twisted or bent. If you have trouble getting your potting soil to absorb water, try using hot water. You also can add in a drop or two dishwashing liquid into the water. Harden off your seedlings by placing them, still in their pots, in the sun for a couple of hours a day for a few days. You don't want to put them in the direct sun for too long, but allow them to build up a tolerance. If you're buying seedlings from a nursery, you still should harden them off before planting. Most of the plants sold in nurseries and home improvement stores are fresh from greenhouses. When planting seedlings, plant them as deep as they were in their pots. The exception is tomatoes, which should be planted deep.
Collecting seeds If you have a plant that you like and want to grow more from seed, chances are you won't get the plant you think you are. Most plants hybridize and the seeds will be a mixture of two or more species. You may end up with a slightly or drastically different plant, Echols says, but that can be fun, growing a plant that no one else has. Make sure you dry your seed well before packaging it for storing. Put it in a paper bag and label the bag with the name of the plant, if you know it, or a description if you don't. Include the date it was collected and any other pertinent information. Once dry, seeds should be stored in a cool, dry place.
People get a big kick out of growing roses from seed, Echols says, and it's easier than people assume. The seeds are in the rose hips. Harvest the hips when they are yellow -- before they turn red. Cut it open and you'll find five to seven seeds. Wash the seeds then put them in damp peat moss, inside a plastic bag. Write the date the seeds went in and the date they need to come out, then store them in the refrigerator for three months. Scatter the seeds on a flat of planting mix and keep them warm. Once they germinate, plant the seedlings, which will start to bloom within three weeks. Rose seeds cannot be stored.
Cuttings If you want a true copy of a plant, try rooting cuttings. You'll need a sharp bypass pruner, perlite, a plastic shoe box with holes punched in the bottom and rooting hormone. Echols recommends Dip & Grow. Take clippings from the plants you want to root. Cuttings as small as an inch and half can be rooted, so you don't need a lot. Longer clippings can be cut above the bud or leaf joint to make multiple rootings. Remove all flowers and buds from the plant, and snip out new growth from the top, which will trigger the plant's instinct to produce more foliage. Prepare your rooting hormone and dip cuttings in it. Cuttings should stay in the solution for at least 10 seconds, but they can stay in for longer periods of time -- not overnight, though, Echols says. Once your cuttings are ready, fill the shoe box with perlite and water it. Then dig a shallow trench in the perlite and pop in your cuttings. They should root within seven to 10 days, although some woodier plants may take longer. Keep the cuttings watered. Use a pencil, fork or spoon to dig down near the cutting and lift it from the perlite the check for root development. Be gentle. If the cutting has rooted, plant it by digging a hole deep and wide enough so as not to disturb, twist or bend the roots. Some plants, such as geraniums and succulents, don't require rooting hormone and can be cut and popped into the ground. For these plants, you may want to wait a day or so have taking a cutting to allow the plant end to callous over. Rooting hormone can be mixed at three strengths -- low, medium and high. Most plants will root well on the low mixture; junipers and redwoods need the high strength. Be careful. If a plant only needs low, it will fail to root if you use the medium or high. Keep track of your methods, successes and failures so you'll know what to do the next time.
Our Garden offers free gardening classes 10 a.m. to 11 a.m. every Wednesday, through October. The garden is located at Wiget Lane and Shadelands Drive in Walnut Creek. Master Gardeners are available to answer your questions and diagnose disease and pests, and there is a wide variety of plants for sale.
Next time in the Garden: Backyard orchard culture with Master Gardener Helen Erickson.