Garden Variety: Spring vegetable seeding and planting calendar

Garden centers are starting to gear up for spring, and some of the first things to hit the shelves are seeds and their companion starting kits.

Starting vegetable seeds indoors can be a great way to fight the winter blues and get a jump-start on your vegetable garden. Just remember that with vegetable planting, timing really is everything.

Vegetable planting calendars are easy to find in gardening books, magazines and in cooperative extension resources. Kansas State University’s planting calendar is a great place to start with consideration to our local weather conditions.

For seed starting, however, planting calendars get a little more complicated. This is generally because they give the number of weeks the plant needs to grow instead of just listing dates. For example, if you wanted to plant tomatoes in your garden this spring and plan to start the plants from seed, guides tell you to start the seeds six weeks prior to transplant date. This assumes you know the best time to transplant the tomatoes into the garden.

To simplify, KSU recommends transplanting tomatoes into the garden in May. Six weeks prior means starting seeds indoors in late March or early April. Starting them too early will most likely result in overgrown, spindly plants by the time the soil is warm enough outside for transplanting. Starting them too late may mean transplanting tender little plants into the scorching summer sun.

What about other vegetables? We are already past the recommended seed-starting dates for cabbage, broccoli, cauliflower and onions. You could still take your chances and hope we have a long, cool spring, but just remember these vegetables prefer cool temperatures. The later the transplants get into the garden, the less likely they are to produce a head of broccoli or cauliflower before heat encourages them to flower and set seed. Onions can still be planted as sets (small bulbs) or plants directly into the garden in March or April.

Peppers and eggplant grow a little more slowly than tomatoes, but are generally started around the same time. Cucumbers, squash and watermelon only need about four weeks. Like many warm-season vegetables, including corn and beans, they can also be seeded directly into the ground in May.

For other vegetables, herbs and flowers, consult planting calendars appropriate for Kansas and the Midwest.

Seeding and planting schedule

Recommended seeding and planting times for commonly transplanted vegetables, based on the 2015 calendar:

Cabbage, broccoli, cauliflower, onions

Time from seed to transplant: 8 weeks

Start seeds indoors: Jan. 24- Feb. 7

Transplant into garden: March 21-April 4

Onion sets, which look like tiny bulbs, can be planted directly into the garden in mid-March or later.

Peppers, eggplant

Time from seed to transplant: 8 weeks

Start seeds indoors: March 14-28

Transplant into garden: May 2-16

Tomatoes

Time from seed to transplant: 6 weeks

Start seeds indoors: March 21-April 4

Transplant into garden: May 2-May 16

Cucumbers, squash, watermelon

Time from seed to transplant: 4 weeks or less

Transplant into garden: May 9-May 23

Seeds can also be planted directly into the garden in May.

— Jennifer Smith is a former horticulture extension agent for K-State Research and Extension and horticulturist for Lawrence Parks and Recreation. She is the host of “The Garden Show” and has been a gardener since childhood. Send your gardening questions and feedback to features@ljworld.com.