Before one can truly understand the Doyle’s Thornless Blackberry® it is necessary to understand the ordinary berries, and maybe you have some of them now.
Here are some important steps to follow during the planting process:
About Our Blackberries
Thornless blackberries are a gardener’s dream. Full delicious berries and graced by lovely flowers and foliage, they lack the two terrors of blackberry growing: there are no piercing thorns and they are not invasive.
The thornless blackberries have a wide range. Blackberries do require some seasonality (about 250 chill hours) so a tropical climate is not for these. Our thornless berries go through zero digits with ease, and have survived -25. We do recommend covering the plant with 6 mil clear or white plastic when temperatures go below minus 20.
Blackberry plants are tolerant of dry conditions but, when fruit sets, they will need watering at least once a week. We package these plants to last 15 days, however, the plants will last indefinitely if put in a hole with dirt around the roots if planting is necessarily delayed. After planting, the roots should be covered and the soil firmed and watered well. After this, very little watering is necessary until fruit production begins.
It is important that blackberry plants should not be located within six hundred feet of WILD raspberries or WILD blackberry plants, nor should they be planted where tomato, potato, eggplant, or peppers grew within the last two years. These plants can be infected with diseases or viruses that can infect blackberries.
Keep plant roots moist until planting time by either heeling them into the ground temporarily or wrapping them in wet burlap. Do not leave the roots exposed to the drying effects of sun and air. Prepare a planting hole large enough to allow the roots to spread out naturally.
Do not prune the roots except to remove damaged ones. Set plants at the same depth they were planted in the nursery. The crown (the point where the stem and root merge) should be at ground level.
After planting, tamp the soil firmly to remove air pockets around the roots. Water all new plantings well, immediately after planting.
Environment and Climate
To plant, dig a hole wide enough and deep enough to take the roots. The crown should be even with the soil line. Blackberries grow in a wide range of soils, but they fare best in well-drained soil. Ideally, pH should be 5.0 to 6.5.
To fertilize, apply Doyle’s Organic 4-4-4 in early spring when growth starts and again in summer three weeks after flowering starts. This is about 4 ounces per 12 inch square around the plant. Mix with soil if applying just to the plant area.
For row planting, allow at least 6 feet between rows to provide room for humans and animals to walk between rows. Space rows 3 foot wider than any equipment such as mower that will be used between rows.
Doyle’s Thornless Blackberry is a trailing blackberry plant and should be set a minimum of 8 feet apart. If you have room and only planting a few plants then we recommend spacing up to 15 foot apart
When to plant
Planting in the spring allows the plant to grow all summer long and will produce lots of fruit the following summer.
Planting in the fall lets the plant grow roots all winter long which will grow a larger plant the next year compared to waiting to plant in the spring.
Full sunlight is preferable, but blackberries will thrive in partial shade. We recommend a minimum of 6 hours direct sun.
Planting during hot weather when temperatures are above 80 degrees is ok but they will require much more attention and daily watering. Providing afternoon temporary shade is recommended for at least 2 weeks.
Mixed fertilizers are satisfactory for blackberries. For best results, apply fertilizer in early spring when growth starts and again in summer when blossoms appear. Use Doyle’s Organic 4-4-4 in early spring when growth starts and again in summer three weeks after flowering starts. This is about 4 ounces per 12 inch square around the plant. Mix with soil if applying just to the plant area.
Blackberries require abundant moisture while the berries are growing and ripening. If rainfall is not adequate, provide irrigation water equivalent to 1 inch of rainfall per week. A minimum rate of drip irrigation for mature blackberry plants is one pint of water per day while berries are developing.
Mulching reduces watering frequency and aids in the control of weeds and grasses that compete for moisture and nutrients. Good mulching materials include pine straw, wood chips, and seed-free grain mulches, such as wheat or rye.
We use black 10 mill plastic around our plants.
Blackberry plantings should be cultivated thoroughly and frequently or mulched very well to keep grass and other weeds from getting a start. Once started, weeds are difficult to control. Begin cultivating in the spring as soon as the soil is workable. Cultivate as often as necessary to control weeds. Avoid deep cultivation so that you do not cut the blackberry roots. Discontinue cultivation at least one month before freezing weather normally begins.
Plants that show symptoms of iron or zinc chlorosis should be treated with foliar applications of iron or zinc sulfates. Plants also can be treated with foliar or soil applications of iron or zinc chelates. Foliar applications of these materials should not be applied during flowering because flowers may be burned.
Growers and gardeners should follow the label rates for best results Training and Pruning We recommend using a shift Trellis and you can find more information on the internet for construction. Basically it is a post in the ground with an upper post attached so it can rotate horizontal during the winter and spring and then raised and tilted in the opposite side for summer harvest. This improves winter protection and gives the fruit shade during the summer. The result is up to 30% more fruit. We are testing some simple designs and plan to have illustrations available soon.
Construct a grape type trellis with 6 foot posts spaced 16 foot apart. Run 12 gage wire at 3, 4, 5 and 6 foot . Run the primary canes along the bottom wire keeping all the laterals on one side of the wires. When the new growth starts for next year run it on the opposite side of the wires. The laterals will naturally grow upwards. Keep them spaced so they can get lots of sun. You will need to attach the canes 2-3 times per week to keep them where you want them. You can use ribbon or binders twine but we recommend the berry klips since they can be reused easily and removing old canes is much easier.
Trailing blackberries should be trained to a fan type trellis with a soft string, ribbon or binder twine. Wire or nylon string could cut the canes bark and kill the cane. Tie the new blackberry shoots to a trellis till they reach 60 to 70 inches in height, cut off the tips. This will force branching lower on the canes and will cause the canes to thicken, making them better able to support a heavy fruit crop. During the winter prune the laterals to 12 to 14 inches for convenient harvesting and larger berries.
In late winter or early Spring, remove any remaining dead or weak wood. Leave healthy, vigorous canes spaced at six canes per linear foot. This method is for gardeners with limited space. Some growers like to use fence or panels which will work but do not run the canes in and out because it will make removing the old canes very difficult and may damage the new canes.
Crop Yield and Storage
Generally, only a small crop of fruit, if any, is produced in the first season. In the second and succeeding years, shoot growth is more vigorous and upright. Tie these new shoots to the trellis when they reach a length of 4 to 6 feet. Some growers prefer to wait until harvest is over and old canes have been removed before tying new shoots to the wires. DON’T with this plant. You will only do it once. When young they are very flexible and easily trained. Handle canes carefully to avoid breaking or forming right angles, which could inhibit the flow of nutrients and water. Ends of canes can be removed without significantly reducing yields.
Berry size may increase when half or more of the cane is cut off, but the number of berries may be reduced. Harvesting The harvesting of blackberries begins about the first of July in Indiana and lasts to September. Pick when the fruit is dull black in appearance. Full ripe, the berry falls into your hand when the bush is touched. The berry is very juicy and does not ship well but makes delicious pies, cobblers and juice.
Slight pull: not as sweet but ships nicely.
Hard pull: pucker.
Begin picking early in the morning before air temperatures become too high. Blackberries become fully black 2 – 3 days before the are fully mature. Shiny blackberries turn a dull black color when they are fully mature. Handle berries carefully when picking. Use shallow picking containers to avoid mashing the berries.
Cool the berries as soon as possible because their quality deteriorates rapidly when they are held at temperatures of 75E°F or higher for more than 24 hours. Berries may be stored reasonably well for 4-5 days at 32-35E°F with a relative humidity of 90 percent.
Blackberries can be irrigated with flood, furrow, sprinkler, or drip systems. Furrow and flood irrigation are generally the cheapest ways to irrigate but are not appropriate for fields or gardens that are not level. Growers with poor quality water should use flood irrigation to prevent the accumulation of salts in raised beds.
Gardeners often prefer sprinkler irrigation due to ease of use. Sprinklers, however, often result in plants with more foliar diseases. Furrow, flood, and sprinkler irrigation techniques increase weed populations between hedgerows in contrast to drip irrigation.
Although drip irrigation is somewhat expensive, it’s the most efficient way of applying water and fertilizer. Because water is generally confined to the root area, weeds are not as prolific in the alleys. Drip irrigation systems apply water more uniformly and require less labor but can be damaged by rodents and cultivation.