Grit Blogs > The Creative Vegetable Gardener

When and How to Plant; An Overall Guide

Karen NewcombVegetables are divided into warm season and cool season crops.  Different classes of vegetables require different amounts of heat in order to grow. 

Generally, plants that we harvest for their fruit (the part of the plant in which seeds are produced), such as tomatoes, squash, peppers, eggplant, melons, and lima beans, need ample heat and long days.  Even when there’s no longer any danger of frost, there must be enough heat during the day to satisfy a plant’s requirements, or it will just sit there and do nothing.  Furthermore, the plants set out early in the season never seem to catch up with the plants set out later; cool weather impedes development.

Cool season plants, on the other hand, do well when the temperature is on the low side.  Generally speaking, these are the leafy and root vegetables, such as carrots, beets, spinach, cabbage, and lettuce.  Peas qualify as a cool season plant even though the fruit is harvested.  When the weather is cool and the days short, these plants put all their energy into forming leafy or root materials, but when the days warm up, they stop this activity and start going to seed.  As a result, you usually have to plant cool season vegetables early so that they can achieve the right size before the weather becomes too hot.  You can also plant them later in the growing season so they mature in the cooler days of fall.

In addition to warm season and cool season vegetables, there are early and late varieties of most vegetables.  The early varieties require less heat to mature than the late ones.  If you want to get to work on your vegetables early, you can start with an early variety, then follow with later varieties of that particular vegetable—all season long.

If you live in an area where the temperature never rises above the 70s during the summer, you might want to plant only early varieties.  It is important to choose varieties that are right for your growing season.

All this means that you have to learn the heat requirements of particular plants in order to know when to plant in your area.  If you want to fool your friends into thinking you’re a veteran gardener, just look for some of Mother Nature’s best clues.  The blooming of fairly common plants will signal the times to start planting far more accurately than arbitrary planting rules.  Watch for these developments, then go to work.

CONDITION                                                                     PLANT 

Development of color in flowers                                    Beets, carrots, leaf lettuce, onions, peas,

from spring bulbs, such as tulips or                              radishes, and spinach


Appearance of plum and cherry blossoms                  Head lettuce  

Appearance of apple, quince, and strawberry             Everything else—cucumbers, melons,

blossoms                                                                           squash, tomatoes, etc.

For quick reference, vegetables can be divided into three categories:

  1. Cool season crops (adapted to 55-70° F) tolerant of some frost:  asparagus, beets, broccoli, Brussels sprouts, cabbage, kale, mustard greens, New Zealand spinach, onions, radishes, rutabagas, spinach, turnips.
  2. Cool season crops intolerant of some frost at maturity:  carrots, cauliflower, endive, lettuce, peas, rhubarb, Swiss chard.
  3. Warm season crops (requiring 65-80° F day and night) readily damaged by frost:  beans, corn, cucumbers, eggplant, melons, okra, peppers, squash, tomatoes. 

Planting by Moon Cycles 

Some gardeners swear by this method.  It’s true that both the moon and the sun affect the tides and that the gravitational pull of the moon is greater at certain times than at others.  If you closely observe the growth of your garden in relation to various phases of the moon, you’ll notice some startling connections.  Spurts of growth seem to coincide with the new moon and the full moon.

Here are some rules old-timers use:

  1. Plant vegetables that grow above ground (such as tomatoes, squash, and lettuce) two nights before the new moon or in the first quarter of the new moon.  You can also sow when the moon is waxing from half to full.
  2. Plant root crops (such as carrots, beets, radishes, and onions) in the third quarter of the waning moon.
  3. Transplant during the waning moon.  The root will take immediately.

Happy planting!

© Copyright by Karen Newcomb