What to plant in April in Iowa

Last chance in April

Bitter Melon (start seeds indoors, by Apr 4) · Bok Choy / Pak Choi (start seeds indoors, by Apr 4) · Cucamelon (start seeds indoors, by Apr 4) · Fennel (Bulb) (start seeds indoors, by Apr 4) · Lettuce (start seeds indoors, by Apr 4) · Luffa (Loofah Gourd) (start seeds indoors, by Apr 4) · Napa Cabbage (start seeds indoors, by Apr 4) · New Zealand Spinach (start seeds indoors, by Apr 4) · Peanut (start seeds indoors, by Apr 4) · Swiss Chard (start seeds indoors, by Apr 4) · Watercress (start seeds indoors, by Apr 4) · Cantaloupe / Muskmelon (start seeds indoors, by Apr 11) · Cucumber (start seeds indoors, by Apr 11) · Pumpkin (start seeds indoors, by Apr 11) · Sunflower (start seeds indoors, by Apr 11) · Watermelon (start seeds indoors, by Apr 11) · Winter Squash (start seeds indoors, by Apr 11) · Zucchini / Summer Squash (start seeds indoors, by Apr 11) · Mache (Corn Salad) (direct sow (spring), by Apr 4) · Pea (direct sow (spring), by Apr 4) · Spinach (direct sow (spring), by Apr 4) · Green Onion / Scallion (transplant outdoors, by Apr 7) · Arugula (direct sow (spring), by Apr 11) · Beet (direct sow (spring), by Apr 11) · Fava Bean (Broad Bean) (direct sow (spring), by Apr 11) · Green Onion / Scallion (direct sow (spring), by Apr 11) · Mizuna (direct sow (spring), by Apr 11) · Onion (direct sow (spring), by Apr 11) · Radish (direct sow (spring), by Apr 11) · Shallot (direct sow (spring), by Apr 11) · Tatsoi (direct sow (spring), by Apr 11) · Cabbage (transplant outdoors, by Apr 14) · Collard Greens (transplant outdoors, by Apr 14) · Horseradish (plant crowns / divisions, by Apr 14) · Kale (transplant outdoors, by Apr 14) · Kohlrabi (transplant outdoors, by Apr 14) · Onion (transplant outdoors, by Apr 14) · Rhubarb (plant crowns / divisions, by Apr 14) · Shallot (transplant outdoors, by Apr 14) · Carrot (direct sow (spring), by Apr 18) · Chervil (direct sow (spring), by Apr 18) · Endive & Escarole (direct sow (spring), by Apr 18) · Kohlrabi (direct sow (spring), by Apr 18) · Lettuce (direct sow (spring), by Apr 18) · Mustard Greens (direct sow (spring), by Apr 18) · Rapini (Broccoli Raab) (direct sow (spring), by Apr 18) · Turnip (direct sow (spring), by Apr 18) · Watercress (direct sow (spring), by Apr 18)

Sow or plant outdoors in April (97)

Direct sowing and transplanting windows that fall in April, most urgent first. Windows are one-to-two-week bands around the ideal date.

Start seeds indoors in April (18)

Indoor sowings for transplants later. Six to eight weeks under lights is typical for tomatoes and peppers; onions and leeks need longer.

Harvesting in April

First harvests expected this month from crops sown or planted on time earlier in the season.

Planting dates for popular crops in Iowa

Every crop has its own full-year dates for Iowa: indoor start, transplant or direct sowing, and harvest.

Last-frost month: April garden jobs in Iowa

1. The average last frost is April 25. Hardy crops can go out now - mache (corn salad), pea, spinach, green onion / scallion - but hold tender ones like tomatoes, peppers and squash until after that date.
2. Start hardening off indoor seedlings 7-10 days before they go out: a few hours of outdoor shade first, building up to full sun and nights outside.
3. Keep row cover or old sheets handy and watch the 10-day forecast - a clear, still night after a warm spell is the classic late-frost setup.
4. Soil temperature matters as much as the calendar: most warm-season seed rots below about 60°F. Check the frost dates guide for how the Iowa average is worked out.

USDA zone chart for Iowa

Iowa spans USDA zones 4b, 5a, 5b. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average.

Questions gardeners ask