How to Grow Blackberries: A Complete Organic Growing Guide

With their sweet, juicy taste, blackberries are perfect for desserts, jams, or simply snacking on. Nothing beats the flavor of homegrown, and they are so easy to grow!

It doesn’t take long to see that cultivated thornless blackberries have only made growing them even easier and more enjoyable. In this comprehensive guide, I'll cover how to grow blackberries, including choosing the right variety, how to plant, caring for a blackberry bush, and harvesting the fruit.

Thornless varieties of blackberries, such as Triple Crown, Caddo, and Natchez, are easier to handle and harvest without the painful thorns found on their wild relatives. Thorny blackberries, like Brazos and Darrow, may produce larger, sweeter fruit but can be more difficult to manage due to their prickly stems.

Everbearing blackberries, such as Prime Ark Freedom, produce two crops per year: one in summer and one in fall. Summer-bearing blackberries, like Chester and Triple Crown, produce one large crop during the summer months, while Natchez is one of the earliest ripening early-season blackberries.

Amending the Soil pH

Whether you purchase bare root plants or potted canes, the soil requirements will be the same. Blackberries like well-draining soil with a pH of 5.5 to 6.5. Conduct a soil pH test and adjust accordingly. 

If you notice the leaves on your blackberry plant getting dark edges or browning, it indicates nutrient deficiencies caused by a high pH. When the pH is too alkaline, you will need to amend it with granulated sulfur before planting and then amend it each year throughout the life of your blackberry plant.

Fertilizing Blackberry Plants

I recommend using a balanced, all-purpose, broad-spectrum fertilizer when fertilizing perennials and fruit trees. It is important to fertilize blackberries twice a season to support high fruit yields.

Blackberries, much like raspberries and other brambles, will fruit on new growth. If you have old canes, you’ll end up with a big tangled mess and no fruit. So, the secret to productive blackberries is to boost new growth every spring by fertilizing. 

Apply a high-quality fertilizer with plenty of nitrogen (I use 1/2 cup of Trifecta+) in early spring and, after the fruit has been harvested, come back and apply a fertilizer with phosphorus (again, I use 1/2 cup Trifecta+) to support the root system as it prepares for dormancy. 

Bone meal is another good organic fertilizer option that contains some nitrogen and a lot of phosphorus. I also topdress with a bit of compost once a year to continue amending and feeding the surrounding soil. 

What To Do When You Receive Bare Root Plants

Dormant plants are often shipped “bare root,” meaning they’re removed from the soil while dormant, and the roots are cleaned of any remaining dirt. This reduces weight—since soil is heavy—and helps lower shipping costs. It also minimizes the risk of spreading invasive species and soil-borne diseases.

If your dormant plants look dead when they arrive, don’t worry; they’re simply in dormancy. The roots will dry out over time, but if they have been shipped properly, they should have retained some root moisture. 

If you are concerned, you can check whether a blackberry plant is still alive by trimming a small piece from the tip of a cane and examining the inside. If the tissue is alive, it will have some light green color in it.

When your bare root blackberry plant arrives, plan to get it in the ground as soon as you can. If you need to wait, keep it in a cool, dark place where the temperature stays above freezing.

On planting day, remove the plant from its packaging and soak the roots in moderately warm water (about 65°F) for up to two hours. This soaking period allows the roots to rehydrate, which is essential for helping the plant come out of dormancy.

Be sure to plant it within a few hours after soaking! Do not allow the roots to dry out again before planting.

How to Grow Blackberries

Blackberries thrive in growing zones 4 to 9, most varieties requiring 300 to 500 chill hours.

Plant bare root blackberries in early spring, while they are still dormant. Container-grown blackberries are best planted in the spring or fall. 

1. Location Selection - Pick a sunny location (with at least 6 hours of direct sunlight each day) and well-draining soil to plant your blackberries. Avoid low-lying areas where water collects and pools, as this can lead to rot and disease later on. 

2. Plant Spacing - Plan to space blackberry plants 3 to 5 feet apart in rows that are 8 to 10 feet apart. Leave room around your blackberries so you can manage their thick growth and volunteer plants.

3. Amend Soil - To prep your planting site, remove weeds and grass, then loosen the soil to a depth of about 8 inches. Amend the soil with 2-5% finished compost to improve fertility and structure before planting. Add amendments for pH and fertilizer.

4. Planting Depth - Dig a hole for each plant large enough to accommodate the root system. Potted canes should be planted at the same depth they were in their containers. Always plant bare root blackberry plants at the same depth as the soil line on the cane. The crown should be 1-2 inches below the surface.

5. Plant - If you are planting a bare root plant, spread the roots out in the hole and backfill the hole with soil. Pro-Tip: You can create a shallow crater in the soil about an inch lower than the surrounding soil level where you plant your blackberries. Water will naturally flow into this slight indentation, keeping the soil more moist and conserving water.

6. Water - Water your blackberries thoroughly after planting. Provide 1 to 2 inches of water per week, either through rainfall or supplemental watering. Pro-Tip: The ideal way to water blackberries is at the base of the plants with drip irrigation.

7. Mulch - Blackberries can benefit from mulching to prevent them from drying out. In our garden, I use shredded wood mulch that we get from a local tree service. Pro-Tip: ChipDrop can help you find cheap, local mulch.

Pruning & Trellising

I learned how to prune blackberries at a U-pick farm. It was unbelievable how much proper pruning increased their blackberry production. One of the biggest mistakes I see gardeners make when growing blackberries is not pruning properly!

Whether you have primocane or florocane bushes makes a huge difference in how you prune them! Use this guide to learn how to prune blackberries and raspberries properly (and how to tell which kind of bushes you have). 

Some varieties benefit from a trellis system that supports the canes, maximizes fruit production, and makes harvesting easier, just like trellising grapes. Simply train the canes onto the trellis as they grow, tying them loosely with garden twine. 

Harvesting Blackberries

Blackberries do not continue to ripen after you pick them, so wait until they are fully ripe before harvesting. Once you start seeing ripe berries on your bushes, pick only the ripe berries off the bush two or three times a week. If you are harvesting thorny blackberries, wear long sleeves, pants, and closed-toed shoes or boots to protect your skin. 

Ripe blackberries are completely black, with no hint of red, and dull instead of shiny. They should feel soft and slightly plump when you touch them, and the berry should detach from the stem very easily.

Pick blackberries by hand, gently grasping each berry and pulling it off the stem. Don’t leave your berry bucket or picked berries in the sun, but cool them off as soon as you can after picking them. 

Take them inside and let them cool to room temperature before putting the dry berries in the refrigerator in a covered container. I recommend waiting to wash them until you are ready to eat them. 

How to Get Free Blackberry Plants From Store-Bought Berries

In the video below, I show how to grow free blackberry plants (or raspberry plants) from fruit that you already have or fruit that you bought at the store. You'll be surprised how simple it is to extract the seeds and grow free plants!