Della's Tips
Della is Dinter Nursery's Greenhouse Manager. Della has been with the nursery over 20 years and enjoys sharing her considerable knowledge and experience. She will provide seasonal tips to help you get more from your garden. This month Della offers:
Starting Plants from Seed
Many books have been written on this subject. Here, to the best of my ability, is a quick summary of how to start your seeds indoors. Please refer to the websites that I have suggested for more detailed information.
Growing your own transplants indoors can give you a head start on the season. For vigorous plants start with high quality seed from a reliable source. Purchase only enough seed for the season, as germination decreases with age. Some seeds such as tomato may last up to 3 years if stored properly.
Seed packages should indicate the year seeds were packages, germination percentage and whether the seeds have received any chemical treatment. Some even have sowing instructions on them. Watch where these packages come from, because sowing instructions may be different in our climate. If there are surplus seeds, or they are purchased well ahead of the sowing date, store them in a cool dry place. Foil packages help ensure dry storage. Paper packages should be kept in tightly sealed containers in the refrigerator, or at around 40°F [4°C].
Some gardeners save seed from their own gardens. You are not always guaranteed that plants will be the same as the parents. Seeds from hybrids will not come true, and seeds from open pollinated plants that are pollinated by insects, and that are within range of another variety may be cross pollinated. Sometimes this results in happy accidents and sometimes not so much! Seed saving is a great skill to acquire.
Water, light, temperature, and oxygen all influence germination of seeds. You need to have an evenly moist environment. Once germination has begun, a dry period can kill the seedling, as can soil that is too wet. Temperature affects the percentage and rate of germination. Some seeds are more forgiving and will germinate under a wide range of temperature, others have a narrow range. It is best to try to keep a steady not fluctuating temperature. Generally 65 to 75°F. [18-24°C] is best for most plants. There are hot pad, heating cables available for purchase. Home heating pads, and even the top of hot water tanks have been used to maintain temperature.
Seeds do need some oxygen, although there isn't a lot of respiration at this time. Make sure that your medium is light and not compact. Overwatering will cause compaction of medium, leading to poor germination and possible fungal diseases. Light can stimulate or inhibit seed germination depending on the species. One of the foremost causes of seed failure is planting the seed too deeply. A great resource for light and depth of planting is found at: www.backyardgardener.com/tm1.html This is an out of print article from Thompson and Morgan seeds. It has a comprehensive list of plants and their individual requirements.
You should always start your plants in a light sterile medium. We suggest a sterile starter mix. This contains peat, vermiculite for moisture retention, and perlite for aeration all ground finely for little roots. The container that you put your moistened soil into should be sterile. you can sterilize your own containers by washing in a solution of 1 part bleach to 5 parts water. There are seed starting trays, and other containers of not too much depth that will allow for good root development. If you are using recycled containers make sure that they have good drainage, and that they are not too deep for the seedlings. If they are too deep, the soil can easily become waterlogged and compacted and this will drown the seeds. It is a good idea to buy reusable plastic containers with divided cells. This will help prevent overwatering, and the spread of fungal diseases.
Once your plants emerge you will require supplemental light if you are growing indoors. Florescent fixtures or grow lights should be suspended 6-12 inches above the seedlings 16 hours a day. Grow tubes are a better choice than cool white ones. This will prevent pale leggy growth, which also makes the plants susceptible to damping off diseases. Damping off is a term that covers several fungal and soil diseases. What happens is that one day your plant is dark at the soil line, and then it lays over and dies. Too much water, non sterile medium, not enough light - all these environmental conditions can lead to loss of seedlings. Make sure that your conditions are optimum.
Seedlings that are just emerging need misting, and good air circulation. A fan in the room will increase the air circulation. You can choose to cover with a plastic dome but always make sure that there is good ventilation. Prevent overcrowding by sowing seeds thinly and transplanting once the true leaves appear, to give more space.
As your plant grows, you must raise your light to maintain the 6 inches above the leaves. If you grow in a bright window without supplemental light, you will need to frequently turn your seedlings to prevent them from leaning and stretching towards the light.
The first leaves that you see are called the seed leaves and these are for the initial nutrition of the plant. You should transplant when the first true leaves appear. You can begin a mild fertilizing at this time as well. Fertilizer should be mainly nitrogen (first number) at this time, as we do not want to encourage flowering yet! Kelpman is a good product for this stage.
Do not transplant into too large a container, as seedlings still run the risk of damping off. Some plants (such as Marigolds and tomatoes) like to be planted deeply at this time as deep as the stems will allow without burying the true leaves. When transplanting it is a good idea to handle your plants by the leaves if possible, so as to not damage the stems. Temperature should still be kept in the 60°F. [15°C] range.
As you get closer to Frost Free days, you could put your seedlings in a warm protect spot outside during the day to gradually harden them off to outside temperatures. Do not transplant outside until all danger of frost is past, usually Mid May in our zone.
Great reference books are:
February 2012
