Starting Plants Indoors

Seeds started indoors require the same basic conditions as those started outside. But since their environment must be artificially maintained, it takes a little more attentiveness. Just as for all plants, the three basic requirements are soil, light and water. But in each case there are special considerations.

It is essential that the soil you use be sterile. One of the great banes of seed growing is a fungus commonly known as Damping-off Disease. The spores of this fungi are ever present in soil and the conditions of indoor gardening seem particularly advantageous to its propagation. It can wipe out hours of hard work in a matter of days.  Use a good potting soil, such as Fertilome potting soil.

After the potting soil has been thoroughly moistened, it can be placed in seeding trays, flats, peat pots, dixie cups, egg cartons, etc. The size of the container will depend on what type of plant you're growing, and often experience is the best gauge. 

A windowsill is not a good location for starting seeds.  Window sills can be the coldest place in the house, especially at night, and then the hottest during the sunny days.  Most seeds need consistently warm soil to germinate and produce strong roots.  You can find seeding heat mats at Pinehurst, that are great to use when germinating seeds.  After the seeds have germinated, remove the heat mats, as they would cause the plants to be too hot.

To promote germination, cover the flats or pots with plastic wrap. Clear plastic grower tray covers, available at Pinehurst, are very handy to use.  This keeps the planting medium both warm and moist, but must be removed as soon after the plants sprout. Otherwise, you risk suffocating your young seedlings.

At this point you will need to keep an eye on things to maintain the proper moisture. If you have a totally artificial setup, you will probably be able to predict how often you'll need to water. If you're using a sunny window sill, you'll need to watch more closely.  

Seedlings need a lot of light.  When seedlings receive insufficient light they become tall and spindly or "leggy."  Even if you have a window that receives full sun, you might need to supplement it with artificial light. If you are using only artificial light, you'll need a great deal of it and much longer growing days. Use bulbs that are specifically made for growing plants and place them just a foot or so above your seedlings. You'll want to keep these lights on at least 14 hours a day. Fluorescent tubes are ideal because they won't produce as much heat, which can quickly dry out your seedlings. 

The third ingredient is moisture, and this is the one that will require the most attention. You want to keep them medium moist, but not let them become wet or soggy. Be careful when watering not to wash the seeds too deep in the soil.

It is important not to start seeds indoors too early. If they outgrow your flats or small pots, you might try thinning them and transplanting the largest to bigger pots, but for the most part you want to plant them outside just as they become large enough to survive transplanting. This is generally four to six weeks after sowing, when they have at least two sets of true leaves. In other words, if you're aiming to plant the first week of May, you probably shouldn't be starting seeds any earlier than mid-March. Toward the end of this period, you may want to provide your seedlings with a little food in the form of a weak, water-soluble fertilizer. We recomend Ferti-lone Geranium and Hanging Basket Food.