Garden Notes March 2026

In Zones 8a and 8b, March marks the transition from cool-season staples to warm-season preparation. With the average last frost date often falling in mid-to-late March/April, our focus shifts to direct sowing and moving established transplants outside. 

Zone 8a Average Last Spring Frost April 1-15 / Average First Fall Frost Nov 1-15

Zone 8b Average Last Spring Frost March 15-April 1 / Average First Fall Frost Nov 15-25

ALWAYS REMEMBER:
All dates are contingent on weather. Keep a close eye on conditions and adjust as needed.

🥬 VEGETABLES

🌱 Direct Sow (Early–Mid March)

These tolerate light frost:

• Carrots

• Beets

• Turnips

• Radishes

• Lettuce

• Spinach

• Arugula

• Kale

• Mustard greens

• Swiss chard

• English peas

• Sugar snap peas

• Potatoes (early March ideal)

💡 Keep soil moist for germination — March winds dry beds quickly.

🌱 Start Indoors (for April transplant)

• Tomatoes

• Peppers

• Eggplant

• Basil

• Tomatillos

Start 6–8 weeks before your last frost date.

🌱 Direct Sow
(Late March – if soil warms)

• Bush beans (late March in warm 8b)

• Sweet corn (late March in warm microclimates)

• Cucumbers (very late March in warm 8b)

Wait until soil reaches 60°F+.

🍓 FRUIT CARE

Plant Now

• Blueberries

• Blackberries

• Raspberries

• Strawberries

• Grapes

• Bare-root fruit trees (finish planting early March)

March Fruit Tasks

• Fertilize fruit trees before bud break.

• Prune peaches, plums, and apples if not already done.

• Spray dormant oil before buds fully open (if needed for scale or overwintering pests).

🌸 FLOWERS

Direct Sow Cool-Season Annuals

• Larkspur

• Poppies

• Bachelor buttons

• Calendula

• Sweet peas

Transplant Cool-Season Flowers

• Pansies

• Snapdragons

• Dianthus

Start Indoors

• Zinnias (late March)

• Marigolds

• Cosmos

• Sunflowers

🌺 NATIVE & PERENNIAL PLANTS

Excellent planting time before summer heat arrives:

• Echinacea purpurea

• Rudbeckia hirta

• Monarda didyma

• Gaillardia pulchella

• Asclepias tuberosa

Plant now so roots establish before summer heat.

🐝 POLLINATOR SUPPORT

• Plant milkweed early.

• Let early herbs flower (cilantro, parsley).

• Add alyssum as a beneficial insect attractor.

• Avoid spraying insecticides during bloom.

✂️ PRUNING – VERY IMPORTANT MONTH

Fruit Trees

Finish pruning before full leaf-out:

• Peaches

• Plums

• Apples

• Pears

Roses

• Hard prune early March (before strong new growth).

• Remove dead/diseased wood.

Hydrangeas

Know your type:

• Bigleaf hydrangeas → light shaping only.

• Panicle hydrangeas → can prune harder.

Ornamental Grasses

Cut back warm-season grasses before new shoots emerge.

🥔 POTATO & COOL CROP CARE

• Hill potatoes once shoots are 6–8 inches tall.

• Harvest outer leaves of kale and lettuce regularly.

• Watch for aphids as temperatures rise.

🧰 MARCH MAINTENANCE

• Refresh mulch but keep away from stems.

• Test irrigation systems.

• Add compost to vegetable beds.

• Begin hardening off seedlings late March in warm 8b.

🌡️ WEATHER CONTINGENCIES

If March is Cold & Wet

• Delay beans and corn.

• Watch for fungal disease.

• Improve drainage.

If March Turns Warm Early

• Start hardening off tomatoes.

• Install trellises early.

• Prepare drip irrigation.

Late Freeze Warning

• Cover strawberries and blooming fruit trees.

• Protect early transplants.