All gardeners are on the lookout for new and interesting plants to add to their garden. Regular trips to the nursery can prove disastrous to the pocketbook, however. One inexpensive way to indulge your planting urge is to grow new varieties from seed. A packet of anywhere from 25 to 100 seeds will cost about what the smallest potted plant does. Here are some tips to ensure success when growing plants from seed.
The first is to have well-prepared soil. Dig your planting bed deeply and amend with compost or other organic material. If your soil is heavy, adding sand can also help improve drainage. Smooth the surface of the soil with a rake, removing larger un-composted twigs or rocks that can create problems for germinating seedlings. Create a small trench and sprinkle seeds at the bottom. Pinch the soil closed over them and pat down lightly. One neat trick is to make a furrow of the appropriate planting depth, sow the seed in the bottom, and cover with packaged soil mix. The mix is high in organic matter and will retain moisture well, and is loose enough that seedlings have little trouble pushing up through it. It will also be a slightly different color than the surrounding soil and make checking the progress of your seeds easier.
Seed packets have lots of good information on them about how deep to sow and how far apart to space rows and plants for optimum growth. Check the packets carefully and follow instructions. Some seeds, such as lettuce and stock, will not sprout under cover of soil. Sprinkle them on the surface of damp soil and then gently tamp them down with the back of your rake or hand. Other advice you could find on the envelope might be that the seeds do best if scarified. Morning glory and sweet pea are two such species. This fancy word just means that some pretreatment is needed to get them to germinate. Usually, nicking the hard outer seed coat is enough, although some seeds may need to be chilled or soaked in water. To get through the seed coat, use a small file or sandpaper and cut or sand anywhere on the seed except at the indentation that indicates where the first shoot will appear. Don’t go too deeply; just until the pale endosperm is exposed. Seeds can also be presprouted between damp paper towels to get a jump on the season. As soon as the first root (called the radicle) appears, plant as deep as indicated.
Consistent moisture is needed to get seeds going. Start with damp soil and then water in with a fine spray after planting. Depending on the weather, you may need to mist as often as twice a day. During very warm and/or dry weather, floating row covers may also help to maintain moisture. Continue with frequent irrigation until plants are well established. Birds (and bunnies) will find your new sprouts a tasty treat, so cover beds with netting suspended by small stakes or wire hoops (croquet wickets are great).
Sowing seed is imprecise at best, so thinning the young plants is usually needed. Once they are an inch or two high, gently pull or snip them off to achieve appropriate spacing. If you are thinning vegetables, most of these sprouts will be fine additions to your salad bowl or sandwich. If you find you have empty spots in your row, fluff the soil slightly and try again. You will have successive harvests of young vegetables and the second group will probably catch up later in the season. Flowering plants will also catch up eventually and even out the display.
Of course, you can also start seeds in containers. Reuse old pots that have been scrubbed out. Commercial potting mixes or your own mix of compost and soil work equally well. All the same rules apply about depth of planting and maintaining adequate moisture, but controlling conditions may be slightly easier. It is a simple matter to create mini-greenhouses with clear plastic bags or used take-out food containers. Wherever you start your seeds, there is no need to fertilize right at the beginning; the seeds carry enough food for the first few leaves. Then you will want to side-dress with a good, well-balanced fertilizer or apply a liquid product. Be sure to mulch the area. Keep mulch thin at first and gradually add more as the plants grow. Seeds are engineered to sprout and grow, so our job is to give them a chance to do just that.
Virginia Hayes, curator of Ganna Walska Lotusland, will answer your gardening questions. Address them to Gardens, The Independent, 122 W. Figueroa St., S.B., CA 93101. Send email to firstname.lastname@example.org.