Vegetable Crop Timing-What do I Plant When


The Vegetable Crop Timing Chart was prepared to help gardeners in southern to central CT understand when to plant their seeds and seedlings. Here is further information to help you in planning your garden.

Cool Season and Warm Season Crops 

There are two categories of vegetable plants- cool season crops and warm season crops. It is important to understand the difference so that your seeds and seedlings will thrive.

Cool season crops grow best in the temperatures of spring and fall.

  • In some cases (radishes, lettuce) a plant will bolt to seedif it gets too hot- meaning it will start flowering and start setting seed. This officially ends the life cycle of an annual vegetable.

  • In other cases (peas) the vegetative vines grow during the cool season. If it gets too hot, the plant flowers and stops growing. If planted too late, you will have short vines and few peas.

  • Cool season crops can tolerate cooler soil temperatures. It is very important to have a soil thermometer and plant your seeds and seedlings when the soil temperature is correct. If you try to rush the season and plant into too cold ground, the crop may be stunted or will fail.

  • Many cool season crops can tolerate a mild frost. Some (kale, Brussel sprouts) can tolerate temperatures well below freezing and get sweeter tasting as the weather cools off.

  • Most cool season crops can be planted in the spring and in the late summer for a fall crop.

    Warm season crops grow best from late spring through early fall

  • Warm season crops should only be planted when the danger of frost is over and when the soil temperature is correct.

  • Warm season crops require the long days and strong sunshine of the summer to grow best.

    Starting plants ahead of time vs. direct seeding

    Many plants need to be started indoors ahead of time in order to give them enough time to mature and ripen in the growing season. In general, you should start your seeds indoors 6-8 weeks ahead of the time you will be planting them outdoors. Seedlings should be gradually hardened off.

  • Cool season crops such as broccoli and cauliflower must be started indoors in order to complete their life cycle before it gets too hot. Sow seeds in late February and plant out as soon as the ground can be worked in late March/early April.

  • Some cool season crops can be started indoors to get a jump on the season but can also be direct seeded in very early spring. Doing both will double your harvest. Examples are lettuce, Swiss chard, and spinach.

  • Root crops (carrots, parsnips, beets, radishes) do best if direct sown. Root crops do not like to be transplanted. If you buy them already started, remove them from their trays, soak them in liquid seaweed water or compost tea, and tease them apart gently before planting.

  • Radishes take a mere 28-35 days from seed to harvest. Plant them weekly to assure an abundant harvest in the cool weather both in spring and fall.

  • Warm season crops such as tomatoes, peppers, and eggplants should be started indoors in order to give them enough time to ripen and mature their fruit. Sow seeds in mid-late March and set out in late May after danger of frost has passed.

  • Some warm season crops can be started in advance but are easier to grow if you direct sow them. Squashes, cucumbers, and pumpkins grow very quickly from seed if direct sown in warm soil in late May and June. If you start them indoors, as tiny seedlings they are often susceptible to pests such as the striped cucumber beetle. This will weaken them.

  • Basil is particularly sensitive to cold. Plant it outdoors ONLY when it has warmed up. 

Direct Sow means to plant your seeds directly in the ground outside.

*Hardening off* You must acclimate your seedlings as they move from indoors to outdoors. Protect from direct sun and wind in a sheltered spot outdoors for one week and gradually move them out in the open.

Vegetable Crop Timing-What do I plant when?

Cold Crops to start indoors in late winter and plant out in April

  • Broccoli

  • Cauliflower

  • Brussel sprouts

  • Early cabbage

  • Lettuce, Mesclun mixes (can also be direct sown in April)

  • Leeks

  • Onions

  • Chard (can also be direct sown in April)  

Cold Crops to direct sow in ground in April

  • Peas

  • Lettuce, mesclun mixes

  • Radishes

  • Collards

  • Beets

  • Carrots

  • Parsley

  • Broccoli Raab

  • Leeks

  • Spinach

  • Salad/stir fry Greens

  • Arugula 

Heat Lovers-direct sow in ground mid/late May
  • Beans

  • Corn

  • Cucumbers

  • Squash

  • Melons

  • Pumpkins

  • Sunflowers

  • Nasturtiums

  • Basil

  • Potatoes- plant organic seed potatoes

Heat lovers to start indoors late March and plant in the ground mid-late May

  • Tomatoes

  • Tomatillos, ground cherries

  • Peppers

      • Eggplants

Heat and cold tolerant crops to direct sow in the ground outdoors in mid-late July for a fall crop

  • Beans

  • Cucumbers

  • Carrots

Swiss chard

Cold Crops to direct sow outdoors in the ground in early-late August for a fall crop

  • Lettuce

  • Radishes (sow every other week after

    weather cools off- ready in 28 days)

  • Kale

  • Beets

  • Carrots

  • Broccoli Raab

  • Spinach

  • Salad/stir fry Greens

  • Arugula

  • Swiss chard

Cold Crops to start 3-4 weeks ahead in pots or an outdoor propagation bed and then plant outdoors in late July/August for a fall crop

  • Cabbage

  • Cauliflower

  • Brussel Sprouts

  • Celery

  • Bok Choy

  • Pak Choy

Plant in late October-November

      • Hard neck garlic cloves



In an effort to provide horticultural information, these educational documents are written by Nancy DuBrule-Clemente and are the property of Natureworks Horticultural Services, LLC. You are granted permission to print/photocopy this educational information free of charge as long as you clearly show that these are Natureworks documents.