What To Plant In August Zone 5

If you’re wondering what to plant in August Zone 5, you’re in the right place. Late summer is a fantastic second season for gardeners, offering a chance to extend your harvest well into fall and even prepare for next spring.

Many people think gardening winds down in August, but that’s not true. The warm soil and slightly cooler nights create perfect conditions for many crops. With a little planning, you can enjoy fresh vegetables and beautiful blooms long after summer’s peak.

Your focus in late summer shifts to cool-season crops that thrive in autumn’s chill. These plants germinate quickly in warm soil and mature as temperatures drop, often tasting sweeter after a light frost. Here’s your essential planting list for August.

Vegetables for a Fall Harvest

These are the workhorses of the late summer garden. You can sow seeds directly into the ground or into containers.

Leafy Greens: Spinach, kale, Swiss chard, and arugula are perfect choices. They grow rapidly and can be harvested as baby greens or full-sized leaves.
Lettuce: Opt for loose-leaf or romaine varieties, which mature faster than head lettuce. Succession plant every two weeks for a continuous supply.
Root Vegetables: Radishes, turnips, beets, and carrots can be planted now. They develop excellent flavor in cool weather. For carrots, use shorter varieties for a quicker harvest.
Brassicas: Direct seed fast-maturing varieties of broccoli raab, kohlrabi, and bok choy. For larger broccoli and cauliflower, you’ll need to use transplants.
Peas: Sugar snap and snow peas love cool weather. Provide a trellis for them to climb on as they grow.

Herbs to Sow Now

Many herbs appreciate the break from midsummer heat and will put on fresh, tender growth.

Cilantro and Dill: These herbs tend to bolt (flower) in summer heat. Planting them now gives you a lush, long-lasting crop.
Parsley: Both curly and flat-leaf parsley are biennials. They will establish this fall and be ready for an early harvest next spring.
Chervil and Chives: These hardy herbs can be sown now. Chives will come back vigorously in the spring.

Don’t Forget Cover Crops

If you have a bed that’s finished producing, consider planting a cover crop. It’s a gift to your future garden. Options like winter rye or clover protect soil from erosion, suppress weeds, and add nutrients when turned under in spring.

Flowers and Bulbs for Future Beauty

August isn’t just about food. It’s a prime time to plant for next year’s color.

Spring-Flowering Bulbs: Order bulbs now for planting in late September through October. Think tulips, daffodils, crocus, and alliums. They need a period of cold dormancy to bloom.
Perennials: Planting hardy perennials in late summer gives their roots time to establish in the warm soil before winter, leading to stronger plants next year.
Fast-Blooming Annuals: Sow seeds of calendula, pansies, or cornflowers. They may bloom late this fall and often survive mild winters to bloom again very early in spring.

Essential Late Summer Gardening Tasks

Planting is just one part of the equation. To ensure success, follow these key steps.

1. Prepare Your Soil

After a season of growth, your soil needs a boost. Clear away any spent plants and weeds. Gently loosen the soil and mix in an inch or two of compost or a balanced organic fertilizer. This replaces nutrients and improves moisture retention.

2. Master Your Watering

August can be hot and dry. Seeds need consistently moist soil to germinate. Water new planting areas daily if rain is absent. Using a light layer of straw or grass clippings as mulch helps retain moisture and keeps soil temperatures cooler.

3. Calculate Your Planting Dates

This is the most important step for timing your harvest. You need to know your first average fall frost date. You can find this online for your specific Zone 5 location. Then, check your seed packet for “Days to Maturity.” Count back from your frost date, and add an extra 14 days as a “fall factor” because plants grow slower in shorter, cooler days.

Example: If your frost date is October 15 and you plant lettuce (50 days), you should plant by August 1st. But for a faster crop like radishes (30 days), you can plant into early September.

4. Implement Season Extension Techniques

Don’t let frost end your gardening. Simple tools can protect your crops.

Row Covers: Lightweight fabric row covers let in light and water but protect plants from light frosts, adding several weeks to your season.
Cold Frames: A simple bottomless box with a clear lid can shield greens and herbs through much of the winter.
Mulch Heavily: For root crops like carrots and beets, a thick layer of straw mulch allows you to harvest them from the ground even after it freezes.

Common Late Summer Problems and Solutions

Stay vigilant to protect your new plantings.

Pests: Cabbage worms and aphids can be active. Check plants regularly. Use floating row covers as a barrier or hand-pick pests. A strong spray of water can dislodge aphids.
Bolting: If you get a heat wave, some cool-weather crops may start to flower prematurely. Keep them well-watered and use shade cloth if necessary to cool them down.
Dry Soil: A crust can form on soil, preventing seeds from sprouting. Cover seeded rows with a board or burlap for a few days after watering to maintain moisture, checking daily for sprouts.

Your August Zone 5 Gardening Checklist

Calculate your fall frost date.
Order spring-flowering bulbs and prepare planting areas.
Clear and amend garden beds for fall planting.
Direct seed leafy greens, radishes, and peas in succession.
Plant transplants of broccoli, cabbage, or cauliflower if you can find them.
Sow herbs like cilantro and parsley.
Water new seeds and seedlings daily.
Apply a thin mulch to conserve moisture.
Monitor for pests and address them quickly.
Plan and assemble your season extension tools (row covers, cold frames).

FAQ: Late Summer Gardening in Zone 5

Can I really plant carrots in August?

Yes! Choose shorter varieties like ‘Nantes’ or ‘Paris Market’ that mature faster. They develop a wonderful sweetness when grown in the cool fall weather.

What if I don’t know my exact frost date?

Use an online lookup tool or contact your local county extension office. For a general Zone 5 guide, plan for a first frost between October 1st and October 15th, but local variations are common.

Is it to late to plant tomatoes in August?

For standard tomatoes, yes, it is too late for a harvest from seed. However, you can look for leftover nursery plants of early, quick-maturing cherry tomato varieties for a small, late crop if you get an long autumn.

How often should I water my new August plantings?

Seeds need daily, light watering to keep the top inch of soil moist. Once seedlings are established, aim for about 1 inch of water per week, from rainfall or watering, delivered deeply to encourage strong roots.

Can I plant perennials and shrubs in late summer?

Absolutely. Early fall is an excellent time to plant most perennials, trees, and shrubs. The warm soil encourages root growth without the stress of summer heat, giving them a head start for spring.

Late summer gardening in Zone 5 is a rewarding endeavor that maximizes your growing space and your harvest. By focusing on the right cool-season crops and using simple protection methods, you can enjoy fresh produce long after your neighbors have put their gardens to bed. The key is to start now—every day counts as we move toward fall.