How To Grow Boysenberries in Your Garden

You can get boysenberry seedlings from your local garden center or plant nursery. Reputable online sellers may also keep these hybrid berry plants. They'll likely arrive having already reached a height of three to seven inches.

Plan your order so that it comes at the right time. If boysenberry plants show up at your door and it's still too cold, you're off to a bad start.

Boysenberry plants are not drought-tolerant and require a moist, well-draining, and nutrient-rich medium to grow. Add some compost to your potting mix for good measure—the soil should be deep. If you're planning a container garden, you'll need a pot with at least a four-gallon volume. Ideally, it will be at least 18 inches wide and 12 inches deep.

When you're ready to plant, till the soil first. The seedlings require three-foot gaps between them, and the holes should be two feet deep and three feet wide. A drink of water will go down well once your plants are in the ground.

For a boysenberry plant to thrive, it needs full sun, so make sure you have an accommodating spot that receives at least six hours of glorious direct sunlight. These conditions don't just ensure optimal growth but the best flavor too. Boysenberries can tolerate some shade.

With adequate moisture, you will get buds and fruit. Boysenberry plants are thirsty, so give them at least an inch of water weekly, and consider recent rain to prevent overwatering and root rot. Water just after sunset during dry seasons.

You can check whether the soil is dry by sticking your finger into the ground up to an inch.

Boysenberries benefit from fertilizer, but they don't need a lot. Fertilize during spring or the latter part of winter when the plant first shows signs of growth, and then later in spring when the plant blooms. You can apply the fertilizer around the base of the bushes.

A balanced 20-20-20 ratio fertilizer works well on sandy soil near the coast. Inland soil benefits from ammonium nitrate.

Although boysenberry plants are most common on the Pacific coast, zones 6 to 9 in the U.S. should do the trick. You can try your luck at zones 5 and 10 too. Above zone 9, plant your boysenberry in the fall. This sensitive plant is heat-tolerant but not cold-hardy, so if your garden is going to get frosty, cover the plants with insulating material.

Trimming boysenberry brambles is essential for their care. Straight after the midsummer harvest is the best time to prune the canes or reaching stalks of this plant. Cut back the old canes to ground level using sharp tools, and make a 45-degree angle cut. Then, secure them to the trellis you use to support your vines, and give the bush a good drink of water.

It's worth noting that year one yields less fruit than year two, so don't be disappointed by an underwhelming initial harvest. Get to pruning, and you'll create the conditions for a stellar harvest the second time around. Pick the black or purple berries in the early morning using a rolling motion—they don't ripen once picked, so leave immature red berries alone.

Yes, and you've got options, but seeds aren't one of them because boysenberries are hybrids! Instead, you can clone the parent plant with a dormant bare root at least a year old with more than two canes. You can root a stem cutting from a friend's plant—take three cuttings for the odds to be in your favor.

In addition, you can try root division or tip layering a trailing first-year cane.

Keep on the lookout for bramble diseases like anthracnose, which causes the ends of canes to die. You may notice gray spots on the foliage initially. Anthracnose and leaf rust aren't death knells like hairy root and crown gall. If you see these latter diseases, you'll have to remove the plant and the affected soil, which can harbor the killer bacteria for years.

Disinfecting pruning tools before cutting may help prevent some of these issues.

Birds love berries, but you can protect your vines with well-stocked bird feeders on the other end of a large garden or bird netting. Insects like aphids, cane borers, and raspberry sawflies are a problem too. The latter requires an application of Spinosad powder, but neem oil insecticides can prevent other pests.

Use a mite control spray on red berry mites.

Train your boysenberries on a trellis. String wire mesh between poles on either end of your boysenberry row or plant them next to a chain-link fence, wall, or garden shed the plants can climb and cling to. Fences allow you to tie the plants off into your desired design. Be creative—something like a ladder could work and make a quirky feature.

Boysenberries belong to the blackberry family in the genus Rubus, as do loganberries and olallieberries. They are a variety of dewberry. These blackberry relatives have a similar appearance but differ in size, color, tartness, sweetness, and firmness.

Boysenberries are not highly toxic, so your cats and dogs should be safe around these plants, although moderation is always a good idea. Be sure to rinse the berries before consuming them. Boysenberries have numerous health benefits and contain anti-inflammatory anthocyanins, so have fun trying them in crisps, pies, and sprinkled over cereal.

The boysenberry plant is pretty rare, so there aren't many cultivars for amateur gardeners. You can choose a thornless variety, but even this type will spring thorns on some canes and young shoots. Upright and trailing options are available. Several varieties are found in New Zealand—the brulee, for example, can be shipped to the States.