Typically in our area April 15th is the time to plant cool weather crops. That being said, the weather pattern seems to be different ever year these days. If the weather cooperates, these are all the early vegetable seeds and root crops I plant around April 15. Asparagus (roots), beet seed, carrot seed, chard seed, kohlrabi seed, lettuce seed, onion sets, parsnip seed, pea seed, seed potatoes (early, midseason, late), radish seed, rhubarb root, spinach seed. The first thing to remember is the ground has to be not so wet as to rot what we plant early. If you till your garden in the spring, you must wait until the soil is drying out. If you till while the soil is still wet it will be hard and clumpy, when it does start to dry out you will need to till it all over again. You certainly can’t plant in rock hard clumps.
Around May 1st I plant broccoli, kohlrabi, onions, lettuce, cauliflower, cabbage and brussel sprouts all as plants.
It is not a good idea to plants tomatoes or peppers in April or early May even if you see them at some of your local garden shops. Planting them in April and early May may stunt their growth and make them more susceptible to diseases. They need warm nights, mid May to the end of May for tomatoes and early June for peppers is a much better time to assure for healthier plants.
There are some annual flowers that tolerate cold weather and light frosts which I'm sure we will still get this spring, these are called the “Hardy Annuals”. They are the most cold tolerant and can take many light frosts. Some will even tolerate freezing weather without being killed. In most cases, hardy annuals can be planted in the spring before the last frost date. Our “Safe” frost date is between the 15th and 20th of May, believe it or not with the way our weather has been. Pansies and violas will definitely get you in the gardening spirit. Keep deadheading them and they will continue to put on their happy faces. Snapdragons remind me of gardening with my grandmother. She would show me how the snapdragons could talk and we would play with them for hours. Depending on the variety you choose, the taller ones look great in the center of a container garden. They also attract hummingbirds. Dianthus as an annual is so hardy that it may even return year after year. The cooler the better for this one. Try these other hardy annuals and biennials in the ground or in container gardens: calendula, cornflower, larkspur, sweet alyssum and stocks. Most hardy annuals are not heat tolerant and usually start to look bad when the cool weather is gone. They may even die when the hot summer temperatures begin. At this time replant with heat loving plants.
Many herbs can be planted in cool weather too. Add them to your flower beds or containers. Here are a few of my favorite choices: Oregano, Thyme, Mint, Marjoram, Rosemary, Sage and Lavender. Plant them with your cool weather flowers for fragrance and different textures.
If you would like to protect your plants this spring from the danger of frost, you may use sheets, burlap, blankets or put large containers on them. Check with your local garden shop, most should carry frost cloth. It is really important to take the covers off your plants in the morning. Plants need air and sun during the day. Just be patient, watching the local forecasts nightly will save you a lot of heartache.