In most cases, it is not cost effective to purchase commercially produced transplants. Transplants typically cost more each than an entire package of seeds, and in the case of root vegetables like carrots, that $3.50 transplant is going to produce ONE very expensive carrot.
There are some exceptions. Perennial herbs are often difficult to start from seed and you only need one or two plants. Commercially, they are usually started from cuttings instead, which is easier, faster and cheaper, and you should consider doing it that way. Taking a cutting from an existing herb plant is your cheapest route to growing your own, but unless you are planning to share a package of 100 seeds with many friends, buying a transplant will get you harvesting sooner. (Provided, of course, you can find the variety you want — herb seeds have their place, too.)
The alternative to commercially produced transplants is starting your own seeds indoors. Starting seeds requires pots, suitable growing media like potting soil, and warm humid environment and very bright light. Pots can be reused from almost any container by poking drainage holes in the bottom, or you can make your own with newspaper. For beginners, a bag of purchased potting soil is probably best but it is cheaper to make your own. Your indoor conditions are probably too cold and dry for warm season crops, and that sunny window is probably not bright enough for strong, healthy plants — if the plants are leaning or get tall, they are not getting enough light. A light fixture, like a 4-tube florescent is really the dimmest light source you can go, and it will produce some heat. If you don’t have a very warm spot (75-80F), heating mats for seedlings can be purchased. A small oscillating fan will also help produce plants with strong stems. For the two plants I start indoors, I have a boiler room which is quite warm and I keep the plants in an old aquarium to increase humidity. So starting seeds has both start-up costs and ongoing energy costs. It also requires a daily commitment of time to ensure the plants have the correct level of moisture in the soil and are doing well.
Is it worth it? Like all things gardening, it depends.
Most vegetable plants do quite well being direct seeded in the garden; often better than transplants. All the squashes and melons like to be direct seeded, as do root crops. Direct seeding saves you time and fussing with pots. Transplants also do not go out in the garden into colder soil and keep growing without a hitch; even with careful hardening off they need 2 or 3 weeks to get acclimated and start growing again, sometimes longer. If you live in an area with a very short growing season, a couple of extra weeks gained by starting indoors may be worth every day. You may also not wish to direct seed if you have problems with critters that eat your seedlings down when they sprout, like slugs. But for most growers and crops, starting plants indoors is of little actual benefit to the plants and harvest. It is, however, an enjoyable late winter activity for many gardeners.
I have two crops I start indoors — tomatoes and peppers. While both will certainly grow well being direct seeded (tomatoes are infamous for volunteering in your garden and compost pile), both plants do not set fruit when the temperature is very hot and humid. Summer rolls in hot and muggy and fast here. The couple of extra weeks I gain by starting indoors makes a huge difference in my harvest. The plants have a chance to set a lot more fruit early on, and of course continue to set fruit when we have breaks in the weather and it cools off. In the case a finicky and slow maturing crop like bell peppers, this means I can start harvesting in July instead of September and typically double or triple the number of peppers I get from each plant. The difference is less dramatic with tomatoes, but still very quantifiable.
We’ve already discussed how much dollar value one can get from tomato plants, and bell peppers are another crop which is very cash positive. If you feel you need to use transplants and cannot afford the start-up supplies for starting your own seeds or are short of time to care for them, buying transplants at the farmer’s market or nursery will be cost effective for some crops. Otherwise, lean toward direct seeding to get your garden going cheaply and with less effort.
(By Nicole Castle)