March is a great time to start thinking about seeding! Daylight hours are very gradually increasing at this time of year, much to the joy of those impatient gardeners out there! If you haven’t already been out to the nursery, the seed racks, soil, packs, and heating mats are all out and ready to go.
Plants to start thinking about now, in the early stages, are petunias, impatiens, geraniums, and peppers. You can also start seeding some of the perennial herbs and other perennials because they take a little longer. This is a great place to start for those of you with itchy hands who are dying to get started!
Many plants can be started indoors fairly early in order to produce a nice plant by the time the weather is suitable for them to be put outdoors for the summer. Begonias, gloxinias, dahlias, canna lilies, as well as calla lilies are all good examples of plants to start early indoors.
Some tips about seeding for the novice gardener:
- Grow lights are a good idea. These are special, full-spectrum light bulbs to ensure the plants are getting the ultra-violet light that they need. You can also get adjustable stands for the lights so that the bulb can be placed at the appropriate height above the soil. When first planted, the light source should be placed about one inch from the soil. As the seed starts to crack the surface, the light can be raised as the plant grows. And the plant will grow much straighter if the light is directly overhead. Another tip is to place a small oscillating fan near the seed tray to mimic outdoor breezes in nature. This will move the plant slightly and strengthen the stem as a result, preparing it for the transition to outdoor planting later on.
- You can buy domes for your seed trays to keep them covered, replicating the greenhouse effect. This will keep the seeds warm and moist, and they will not require much watering, maybe just a misting every other day. Once the seedling has broken the surface and is up nice and straight, you can remove the dome during the day, replacing it at night.
- Avoid fertilizing at this early seed stage. Most soil mixes have a very small amount of fertilizer in them anyway, and there is little or nothing there to take up the fertilizer. So, if the seedling has broken the soil, a regular fertilizer like 20-20-20 could burn the seedling right off as soon as it cracks the seed. You should never fertilize until your plant has its second set of “true leaves.” When it first cracks the surface, it will have “seedling leaves,” then a set of “true leaves,” and then a second set of “true leaves.” At this point, you can begin fertilizing.
- When transplanting your seedlings from the seed tray to a pot, be very careful not to pull it by the stem as you could very easily damage that stem. Using a small spoon or popsicle stick, just loosen the plant from the tray, then grab a hold of a leaf and transplant it into a pot. Remember that most plants like to be tight in a pot, so don’t transplant a little seedling into a one-gallon pot. A good rule of thumb would be a seedling into a 4-inch pot. Once your plant outgrows the 4-inch pot, then you can go to a 6-inch or a 1-gallon. It is very easy to overwater a plant in a pot that is too large. The plant just can’t absorb that much water. The top two inches of soil should pretty much dry out before you water again. Overcast days, which are quite common in the spring, can affect your watering schedule. Your plants will not dry out as quickly and may not need water on your
- Only grow as much as you need! When you buy a packet of seeds, you may get 1,200 seeds but . . . are you really going to need 1,200 radishes, for example? Pay close attention to how much you are planting to avoid overwhelming yourself and just dumping plants at the end of the season. Vegetable seeds can maintain their viability for two or three years if they are kept in an air-tight container. Many vegetables are suitable for “succession planting” where you plant a new row every two or three weeks and harvest a continuous crop throughout the season. Radish is a quick crop, ready to eat after only about three weeks. Lettuce, peas, and many other vegetables fall into this category as well. Onion seeds and most flower seeds lose their viability after one year, so with those, it is a good idea to purchase only what you will use this season.
March is also the time when you want to replant your house plants. For many people, this takes a lot of patience and self-control! Midwinter is not the time for repotting. Your plants are in a semi-dormant state—not growing, not taking up nutrients, and not absorbing water the same way as usual. The good news is they come back to life in March with more sunlight hours, and they want more space, more water, and more nutrients, just like those outdoor plants. When you do replant, it is important to increase by only one pot size. If it is in a 4″, go to a 6”, and if it is in a 10″, go to a 12″.
Of course, whatever the size of the pot you need, we have them here at Blomidon Nurseries. And if you haven’t been in to see us recently, the obvious question is, “Why not?” We are here to answer your springtime gardening questions and to supply your seed planting needs.