Going to Seed

A Little Effort for More Choice, Less Money

Robert Daniels, seeding a pot in the sunroom of his Rockville home. Below, seeds are misted, not watered. (Timothy Jacobsen For The Washington Post)

There is a reason people don't start plants from seeds anymore: It is a multi-week chore that is fraught with problems.

But Robert Daniels can think of one good reason to give it a go. "Browallia" he says, tapping seeds into a six-inch pot. "It's a shade-tolerant annual and gives you a blue that impatiens can only dream about."

But don't look for the plant at the garden center in May, said Daniels. In spite of its beauty and utility, it is difficult to find. By starting from seed now, Daniels will have dozens of little browallias to plant in his Rockville garden this spring. By summer, his shady borders will be full of the violet-blue flowers.

Daniels is a gardener by trade, so seed starting is a natural part of his late-winter regime. But all gardeners, say he and other pros, should continue this waning art for both its practical and psychological benefits.

The decline in the practice of starting from seed is measured in the size of young plants sold to consumers at garden centers. Six-packs are old hat -- four-inch pots are now typically the smallest size, and annuals in six-inch pots are more the norm as consumers are willing to pay for the convenience and instant impact of annuals raised to near-maturity.

There are two fundamental benefits to raising plants from seed. The first is that you open up a world only glimpsed at the garden center. As comprehensive as a retail nursery's stock may be, it is not as deep or broad as it might be. One seed catalogue alone, the Tomato Growers Supply Co., lists 235 tomato varieties, including one called Dorothy's Green that looks so unripe when ripe, it must taste great.

The second is that seed starting can save a fair amount of money. Even with seedling attrition, you can raise a dozen tomato plants from a $2 seed packet, versus paying $3 to $6 per plant in May. If you had large flower borders to fill in summer, or an expansive woodland floor to perk up with columbines or foxgloves, it would pay to become proficient in the skill.

Cultivating seed is not a complex endeavor, but there are missteps to avoid. The first is the growing medium, which must be sterile and inert. Stay away from garden soil, bags of top soil and unsterilized compost, which can carry diseases that will kill seedlings.

Many horticulturists use a product called Premier Pro-Mix, and then blend it with sand, perlite or vermiculite. Daniels likes to blend two parts Pro-Mix to one part each of vermiculite and perlite, and mixes them by hand in an old, enameled 10-gallon canning pot.

The mix is moistened to dampen the peat in it, and then packed quite densely in a plastic nursery pot into which most or all of the contents of a packet will be sown, spaced carefully to avoid crowding. Types of containers are as varied as gardeners themselves: Daniels prefers recycled garden center pots, but others use foam coffee cups speared at the bottom for drainage, or specially designed seed flats. Daniels said you should fill the seed pot to the brim to keep the seedlings high and away from stagnant air in a partially filled pot.

Many gardeners I know stay away from peat pots, which are meant to be transferred directly from growing bench into garden soil. They complain that they don't break down quickly and impede the plant's root growth.

For small seeds such as begonias or amaranth, Daniels tamps a top layer of vermiculite to prevent the specks from sinking into the Pro-Mix. Seeds are misted, not watered, and their pot is then placed in a drainage tray. Avoid watering from above, and even bottom watering can result in pots that are sodden and deathly for seeds. You can mist every day or place a clear plastic sheet over the containers until the seeds germinate, usually within a week or two. At that point they will need light, and gentle watering so that the growing medium stays moist but not wet.

A greenhouse is ideal for nurturing baby plants, but few home gardeners have such a luxury. Cold frames are useful for hardy plants that have already germinated, but if you haven't built or bought one at this critical moment for seed starting, your time is better spent raising seeds indoors. After germinating, outdoors is fine for hardy annuals such as lavatera, which must be brought in at night. Some seed packets are better than others at giving detailed information, and few explain that the best time to sow certain hardy annuals, such as larkspur and annual poppies. is in the early fall. Web sites often give more detail.

Windowsills and sunrooms work well if they are bright, but even here trays may need supplemental light to prevent seedlings from stretching and bending. For darker places, including basements, artificial lights work well as long as the fluorescent tubes are kept within six inches of the seedlings. An incandescent bulb will not give the light coverage needed for a tray of seedlings.

Retail and mail-order nurseries sell custom-made growing apparatus that feature seed trays below adjustable lamps, usually with lighting tubes designed for plant growth. These light carts are handy, but often expensive. Daniels paid "close to $300" for his, which he feels is worth it, given its years of use and convenience.

Other gardeners are quite happy to string a couple of shop lights over a workbench, though the lamps must be hung on chains so they can be raised as the seedlings grow. Daniels also uses a heat mat placed under the seeded pots to warm the soil and increase the germination rate. The seedlings need a fan nearby to keep the air moving, both to prevent fungal diseases and to make the stems stouter.

Once the first pair of embryonic leaves gives way to true leaves, the seedlings are moved to larger pots where they can develop sturdy root systems. This is important. For Daniels, this means moving them to empty six-packs that he has accumulated over the years. These cells, about an inch-and-a-half deep and an inch across, allow sufficient room for a seedling to grow to bedding size, which takes six to eight weeks.

How do you move infant plants without breaking stems or damaging fine roots? Very carefully.

The object of starting seeds in the first half of March is to have seedlings that will be ready to plant in early May, after frost danger has passed and garden soil has begun to warm. But the seedlings must be transitioned first by placing them outdoors in a shady and sheltered spot about a week before setting in the ground.

Daniels places them under a raised piece of lattice to shield them from the sun. The seedlings need protection from the high winds and heavy rain common in late April. Once the seedlings are planted in their permanent locations, protect them from slugs and cutworms, measures you would take with nursery-bought seedlings as well.

All this elevates seed starting to the status of a hobby, albeit for just a few weeks. One of the payoffs is in watching your thumb turn wonderfully green.