If you’re a gardener in zone 7, knowing when to plant blackberries is the first step to a successful harvest. The optimal timing for planting gives your new canes the best start, leading to healthier plants and bigger yields in the coming seasons.
This guide will walk you through the best times to get your blackberries in the ground, along with clear steps for planting and care. We’ll cover everything from selecting the right varieties to preparing your soil, ensuring you have all the information you need.
When To Plant Blackberries In Zone 7 – Optimal Timing For Planting
The absolute best time to plant bare-root blackberries in zone 7 is in late winter to early spring. Aim for a window between late February and early April. The key is to plant while the canes are still dormant (before they break bud) but when the ground is workable and no longer frozen.
For container-grown blackberries, which are more forgiving, you can extend the planting season. Early spring is still ideal, but you can also plant in the fall, from late September to mid-October. Fall planting allows the roots to establish in the cooler soil without the pressure of supporting top growth.
Why This Timing Works Best
Planting during dormancy lets the plant focus its energy on developing a strong root system. When spring rains and warmer temperatures arrive, the plant is ready to support vigorous new cane growth. Missing this window and planting in late spring or summer stresses the plant, as it must cope with heat and drought while trying to establish roots.
Fall planting works on a similar principle. The soil is warm, which encourages root growth, but the air is cool, which minimizes stress on the foliage. The plant gets a head start and is ready to explode with growth the following spring.
Understanding Your Zone 7 Climate
USDA Hardiness Zone 7 includes areas with average annual minimum temperatures of 0°F to 10°F. Winters are relatively mild but can have solid freezes, and summers are warm to hot. This climate is actually excellent for blackberries.
Knowing your first and last frost dates is helpful. In zone 7, the last spring frost typically falls between early April and mid-April. The first fall frost usually arrives between mid-October and early November. Use these dates to guide your precise planting schedule.
Choosing the Right Blackberry Type for Zone 7
Before you plant, you need to pick a variety suited to your garden. Blackberries come in different growth habits, and choosing wisely affects how you’ll manage them.
- Erect Thorny: These varieties grow upright and are very cold-hardy. They need less support but have thorns. Examples include ‘Cherokee’ and ‘Cheyenne’.
- Erect Thornless: A great choice for easy picking. They are also upright and cold-hardy. ‘Natchez’ and ‘Ouachita’ are popular zone 7 choices.
- Trailing/ Semi-Trailing Thornless: These have long canes that need a trellis for support. They are often very productive and flavorful. ‘Triple Crown’ is a superb semi-erect thornless variety for zone 7.
Also, pay attention to whether a variety is floricane-fruiting (summer-bearing) or primocane-fruiting (everbearing). Floricanes produce fruit on second-year canes. Primocanes can produce fruit on first-year canes in late summer and again on those same canes (now second-year) the following summer. ‘Prime-Ark® Freedom’ is a primocane type that does well in zone 7.
Step-by-Step Planting Guide
1. Site Selection and Preparation
Blackberries demand full sun—at least 6 to 8 hours of direct sunlight daily. They also need well-drained soil; wet feet will cause root rot. Avoid sites where tomatoes, potatoes, peppers, or eggplants have grown recently, as they can leave behind soil-borne diseases like verticillium wilt.
Prepare the soil several weeks before planting. Blackberries prefer slightly acidic soil with a pH between 5.5 and 6.5. You can test your soil and amend it accordingly.
- Work the soil to a depth of 12-18 inches.
- Mix in generous amounts of compost or well-rotted manure to improve fertility and drainage.
- If drainage is poor, consider planting in raised beds.
2. Planting Bare-Root Canes
- Soak the bare roots in water for 1-2 hours before planting.
- Dig a hole wide and deep enough to spread the roots out comfortably.
- Place the plant in the hole, ensuring the crown (where the stem meets the roots) is level with or just slightly below the soil surface.
- Backfill with soil, gently firming it around the roots to remove air pockets.
- Water thoroughly after planting.
3. Planting Container-Grown Plants
- Water the container thoroughly a few hours before planting.
- Dig a hole twice as wide as the container and the same depth.
- Gently remove the plant, tease out any circling roots, and place it in the hole.
- Backfill and water deeply, just like with bare-root plants.
4. Spacing and Initial Care
Proper spacing is crucial for air circulation, which prevents disease. Space erect varieties 3-4 feet apart in rows 6-8 feet apart. Space trailing varieties 5-8 feet apart in rows 8-10 feet apart.
After planting, cut the canes back to about 6 inches tall. This encourages new, strong growth from the base. Apply a 2-4 inch layer of mulch (like wood chips or pine straw) around the plants to conserve moisture, suppress weeds, and regulate soil temperature. Keep the mulch a few inches away from the canes themselves.
Caring for Your New Blackberry Plants
Watering and Fertilizing
Consistent watering is vital, especially in the first year and during fruit development. Provide 1-2 inches of water per week, more during dry spells. Drip irrigation or soaker hoses are ideal as they keep foliage dry, reducing disease risk.
In the first year, fertilize lightly in early spring with a balanced fertilizer (like 10-10-10). Over-fertilizing, especially with nitrogen, can lead to excessive leafy growth at the expense of fruit. In subsequent years, you can apply fertilizer based on soil test results or when new growth begins in spring.
Training and Pruning
Training your blackberries onto a trellis keeps the garden tidy, improves air flow, and makes harvesting easier. A simple T-trellis with wires at 3 and 5 feet high works for most types.
Pruning is essential for health and productivity. For summer-bearing (floricane) varieties:
- Summer: Tip-prune new canes (primocanes) when they reach 3-4 feet tall to encourage branching.
- Winter/Early Spring: Remove all dead, diseased, or damaged canes. Thin the remaining floricanes to 4-6 of the strongest per plant.
For primocane-fruiting types, you can choose to mow all canes to the ground in late winter for a single, late-season crop on new canes. Or, you can use the two-crop system and prune as you would for summer-bearing types.
Winter Protection in Zone 7
Most blackberry varieties recommended for zone 7 are plenty hardy. However, in particularly harsh winters or for less hardy trailing types, a little protection helps. After leaf drop, you can mound a few inches of soil or mulch around the base of the canes. For trailing varieties trained on a trellis, you can untie them and carefully lay the canes on the ground, covering them with a row cover or mulch for the winter.
Common Problems and Solutions
Even with the best timing, you might encounter a few issues.
- Poor Fruit Set: Often caused by inadequate pollination or late spring frosts. Ensure you have good bee activity and choose a site less prone to frost pockets.
- Orange Rust: A serious fungal disease. Look for bright orange spores on leaves in spring. Infected plants must be dug up and destroyed entirely; do not compost them.
- Cane Borers: These insects cause cane tips to wilt. Look for two rings of punctures below the wilt. Prune off and destroy the affected cane tips well below the damage.
Good sanitation—removing old canes and fallen debris—and proper spacing are your best defenses against many fungal diseases like anthracnose and botrytis.
FAQ: Planting Blackberries in Zone 7
Can I plant blackberries in the summer in zone 7?
It’s not recommended. The heat and dry conditions put tremendous stress on new plants, making establishment difficult and increasing the risk of failure.
What is the latest I can plant blackberries in the fall?
Aim to plant at least 4-6 weeks before your first hard frost is expected. This gives the roots enough time to anchor in the soil before winter dormancy.
How soon after planting will I get fruit?
You may get a small handful of berries in the first summer if you plant in spring, but the first substantial harvest typically comes in the second full growing season.
Do I need two blackberry plants to get fruit?
No, blackberries are self-fertile, so you only need one plant to produce fruit. However, planting more than one variety can extend your harvest season.
Can I grow blackberries in containers in zone 7?
Yes, choose a large container (at least 15-20 gallons) and a compact, erect variety. Provide a trellis for support and be vigilant about watering, as containers dry out faster.
By following this guide and sticking to the optimal planting windows for zone 7, you’ll give your blackberry plants the foundation they need. With proper site selection, planting technique, and ongoing care, you’ll be well on your way to enjoying sweet, homegrown blackberries for years to come. Remember, patience in the first year pays off with abundant harvests later.