It’s time to take the cool-season vegetable seeds you’ve purchased and plant them indoors so that they will be ready to set out in the garden in mid-March. Cool-season vegetables include cabbage, broccoli, cauliflower, kale, spinach, mustards and collards. There are many more but these are the most commonly planted. We start these seeds on or about February 20th.
Start your seeds in small trays or jiffy plugs. Once you have planted your seeds water thoroughly. Remember that until they emerge they will not need much water but do not let them dry out. Of the ones mentioned above, all but spinach will emerge (germinate) in approximately 7 days. The spinach will take approximately 14-21 days.
Let them grow for 7 more days in the containers you started them in. By this time they will need bright light: in a sunny, cool window with direct sunlight all day (south-facing is best), or under grow lights (if under lights they need to be close to the light bulbs to get enough light; not just sitting on a desk or a counter). Without high light, the seedlings will etiolate: that is, they will stretch for light, with long, weak, pale stems.
If you desire, after 7 days re-pot to bigger pots. On the 14th day from germination, you should start to acclimate them to cool (not cold!) temperatures by putting them outside in the day and bringing them back in at night if temperatures are forecast to fall below 35 degrees. Remember that even in winter/early spring the light outdoors is stronger than what they are used to. The first couple of days set them in the light shade until they toughen up, then move them to full sun. They also should be protected from strong winds. Seedlings, especially stretchy ones, tend to bend at the soil line and eventually break if they are put into a windy spot when first going outdoors. This acclimation process will get them ready for planting into your container or garden.
Meanwhile, you should start getting your container, raised bed, or ground bed ready for planting. Remember good soils (soils that drain well and have had organic material such as compost added) and fertilizers are a must for success. If you have been routinely adding compost to your ground bed, you may not need much fertilizer, but if not, you will likely need to fertilize. Remember that while the soil is cold, organic fertilizers may not be effective: they require bacteria to break them down before the plant can use them. Bacteria go to “sleep” in cold soil. Beginning on March 15th you can start planting your plants in their final place. The success of any plant is controlled by good watering habits, soils & fertilizers.
One key thing with early planting in the ground: if the soil is wet/soggy, wait a few days. Walking on/digging in wet soil compresses it and ruins the drainage. If you can make a mudball, then the soil is too wet to be worked. This should not be a problem in raised-bed or container gardens.
By Sissy McKenzie, Beltsville Store Manager
Photo Credit: www.flickr.com/photos/urban-garden-solutions