Living Here Guide

An Idaho gardening to do list for April

Begin seeding tender plants such as eggplants and sweet peppers indoors using bottom heat.
Begin seeding tender plants such as eggplants and sweet peppers indoors using bottom heat.


Feed the dirt. Start adding compost to your soil. One half inch depth of compost should be on beds before planting anything outdoors.

Veggie starts. Begin seeding tender plants such as eggplants and sweet peppers indoors using bottom heat. Sow tomato seeds using bottom heat indoors at the end of the month and basil and other herb seeds at room temperature. Outdoors, plant potatoes, peas, spinach, lettuce, carrots, beets, radishes, kohlrabi, onions and Asian greens as soon as soil temperature is at least 40 degrees F for a few days. then direct-seed cole crops such as broccoli, cabbage, cauliflower and Brussels sprouts or harden-off (acclimate) brassica seedlings. This is usually about St. Patrick’s Day.

Spring blooms. Watch daffodils for blooming; if leaves come up but flowers don’t follow, use slow release fertilizer or dig and divide.

Protection. Remove remaining protective winter mulch from perennial beds, trim out old foliage and apply mulch for summer as soon as true leaves develop. Mulch will conserve moisture and help prevent weeds. Cover emerging seedlings and transplants with agricultural fleece to protect from birds.

Start now. Plant bare-root roses and trees, breaking up caliche if trees will be taprooted. Expect roller-coaster temperatures. Don’t get impatient and transplant frost-tender plants outside too early.

Quick check. If we have a wet spring, watch fruit trees closely for disease: pears, apples and quince for fireblight (black, scorched-appearing twigs, amber ooze), and peach leaf curl on peaches and nectarines.


Time for a trim. Prune roses and apply crabgrass pre-emergent treatment to lawn when forsythia blooms. Shear back groundcovers and decorative grasses and wake up your flower beds with a general fertilizer.

Mind your mowing. Set lawn mower to mow grass at three inch height to shade out areas where weed seeds could establish.

Feed them. Start fertilizing roses, to continue monthly until August.

Divide and conquer. Divide hostas and daylilies if spreading is desired. Set up supports for peonies, delphiniums and other “floppers.”

Plant conifers and shrubs. Also plant summer-flowering bulbs: alliums, cannas, hostas and daylilies.

Get in shape. Prune lavender to shape after it shows signs of new growth. Prune buddleias, shrub dogwoods and caryopteris; prune other spring-blooming shrubs immediately after they bloom.

Time for a skim. As soon as new growth appears, skim soil to remove weed seedlings, and apply organic mulch to bar weeds.

Watch for weather. Protect tender plants from frost. Begin hardening off frost-tender seedlings to acclimate them to direct sun and wind.

Watch for pests. Watch for aphids and knock them from plants with a blast of water. Beneficial insects will take over soon.