Planting a smart vegetable garden

Considering which vegetables you like, how much space you have for them and how you'll meet their growing requirements will help you achieve a rewarding harvest.

Green plants in garden.Thinking about planting your own vegetable garden may bring to mind images of bountiful fresh and healthy produce. Advance planning will be the key to your successful garden. Considering which vegetables you like, how much space you have for them and how you’ll meet each crop’s growing requirements before planting will help ensure you reap the full rewards at harvest.

When to plant?

Last frost date

Before planting your garden, determine the chances for a killing frost in your area by checking the frost-free chart. This chart lists probable dates for the first and last frost of the year throughout Michigan, and helps you determine when you can first plant without minimal risk of a killing frost. Many people plant after the 50 percent probability date. If you plant before this date, there is a greater chance your transplants will freeze or seeds rot and will need to be replaced.

Cool-season and warm-season vegetables

Cool-season vegetables such as lettuce, peas and spinach will thrive early in the season. Tomatoes, peppers and melons will perform best when air and soil temperatures are much warmer. Warm-season crops are more sensitive to late-season frosts, and may show signs of stunted growth if set out too early. 

Soil temperature

Some seeds, such as certain extra-sweet corn cultivars, will not germinate well unless the soil temperature at planting depth exceeds 60 degrees Fahrenheit. Beets, carrots and radishes will germinate at a minimum of 40 F. Planting seeds before reaching this soil temperature will result in little to no seed sprouting. See a condensed table of soil temperatures required for seed germination by University of California at Davis below.

Soil Temperature Conditions for Vegetable Seed Germination

Vegetable type

Soil temperature (F) for seed germination

Minimum

Optimal range

Optimum

Maximum

 

 

 

Cool Season

Beets

40

50-85

85

95

Carrot

40

45-85

80

100

Lettuce

35

40-80

75

85

Peas

40

40-75

75

85

Radishes

40

45-90

85

95

Spinach

35

45-75

70

85

Warm Season

Beans

60

60-85

80

95

Corn

50

60-95

95

105

Melon

60

70-95

95

105

Pepper

60

65-95

85

95

Tomato

50

60-85

85

95

*Daily fluctuation to 60 F or lower at night is essential. Data Compiled by J. F. Harrington, Dept. of Vegetable Crops, University of CA at Davis

Smart choices – seeds or transplants?

Vegetables can be grown from seeds or small starter plants called transplants. Seeds provide a wider selection of vegetables than what you can usually find as transplants, but will take more planning and time to establish. You may have to start some seeds, like tomatoes and peppers, indoors so they reach maturity by the end of the growing season. Information on seed packets contain a treasure trove of information to help you be a successful smart gardener.

What does a seed packet tell you?

  • Plant description: Is this a vegetable? Annual or perennial? What are its characteristics? Is this plant resistant to disease or viruses?
  • How to plant: The seed depth, proper spacing and is thinning recommended?
  • Days to germination: How long will it take for the seed to sprout and grow?
  • Days to maturity: How long until harvest?
  • Light required: Sun or shade?
  • Packed for: Gives the date this seed is good for the highest percent germination.

Seed types

Each seed type has something to offer depending on your needs, interests and values.

  • Hybrid seeds are created by crossing two different parent varieties from the same species. They combine the best traits of these varieties to produce greater disease resistance, yield and uniformity. F-1 means the first generation offspring. These seeds are not genetically modified, but are created using traditional plant breeding techniques.
  • Open-pollinated seeds have more genetic diversity and often more variation than hybrids. Pollination occurs by insects, birds, wind, humans or other natural mechanisms.
  • Heirloom seeds are open-pollinated varieties that have been handed down for generations in a particular region or area, hand-selected by gardeners for a special trait. 

Selecting transplants

Purchase transplants from a reputable source. Many retailers provide disease-resistant cultivars for various vegetables such as late blight-resistant tomatoes. Thoroughly inspect plants for signs of insects by checking under leaves and around stem tips. Avoid plants with leaves that are browning, spotted or wilting. A taller plant doesn’t mean a healthier or sturdier plant. If plants do not receive adequate light while developing, they often stretch toward the light and are weakened.

Smart planting techniques for transplants and seeds

Hardening off

Pink and green foliageBefore placing transplants in your garden, “harden them off” to acclimate them from growing in a controlled greenhouse environment to your garden’s growing conditions. Start by placing transplants outside in a shaded and protected area for a few hours a day and keep them thoroughly watered. Over seven to 10 days, gradually increase the time. They will soon become accustomed to outdoor conditions. When your transplants are ready to be planted, thoroughly water them in their containers and make sure the garden soil is well-watered. 

Remove flowers

Transplants benefit from having their flowers removed at planting. This ensures the plant’s energy goes toward root development, which will be essential with transplanting. Sacrificing those initial flowers increases flowering (and fruiting) throughout the season.

Mulching

Apply a 1- to 3-inch layer of organic mulch around the plant’s base and not against the stem. Mulch will help maintain an even soil temperature, conserve water and help reduce competition from weeds. If transplants are tall, provide staking as necessary.

Succession planting

Planting seeds on multiple dates throughout the growing season can provide continual harvests of earlier maturing vegetables. For example, plant seed lettuce and other greens every two weeks, or plant radish seeds every three to four weeks for a continuous supply.

Maximize your space

Use every growing layer or tier within your garden. Root crops grow deep into the soil while tomatoes mature above ground. Lettuce is shallowly rooted and will grow as living mulch atop root crops such as beets and carrots. Plant carrots around developing tomato transplants or lettuce around developing root crops such as onions or radish. You can also increase your garden’s yield by growing vining crops such as tomatoes, melons, pole beans and cucumbers on trellises or any vertical structure. Harvesting is also easier, as there’s no stooping or hunching over!

Invite pollinators and other beneficial insects

Smart gardeners intersperse flowering herbs, annual flowers and native perennials among the vegetable garden. These plants add diversity to your garden, provide valuable food and shelter for native pollinators and beneficial insects that provide natural pest protection in your garden.

Vegetable garden with different plants.

Planning for diversity within the vegetable garden is a smart gardening practice.

For more information on a wide variety of smart gardening articles, or to find out about smart gardening classes and events, visit the Gardening in Michigan website.

Related Events

Related Articles

Related Resources