Growing blackberry bushes is a rewarding process that will result in delicious fruit the season after you first plant the bushes. In order to ensure your blackberry plants get off to a good start, you need to pay attention to fertilizing and watering.
Fertilizing Your Blackberry Bushes
Blackberries require fertilizer, but only at certain times. Look closely at the leaves. If they appear to have good color and the plant is fruiting and growing well, you do not need to fertilize. Should you determine fertilizer is required, rake back the mulch, spread the fertilizer on top of the soil and replace the mulch.
If you use compost, manure or another organic fertilizer, apply it in the late fall before the first frost. Blood meal, cottonseed meal, fish meal or alfalfa meal are other alternative organic fertilizers. You will need to apply approximately 50 pounds of organic fertilizer per 100 feet.
In early spring, just as grown starts to appear, spread inorganic fertilizers over the top of the soil in each row. Apply 5 to 6 pounds of 20-20-20 fertilizer per 100 feet of row.
In midsummer, or at bloom, if your blackberry bushes appear to be lackluster, you can apply an additional pound of ammonium nitrate per 100 feet. Do this just before watering.
Watering Your Blackberry Bushes
Watering is critical for first-year blackberry bushes. Of course, you need to water them well after you plant them, but their water requirements after that are pretty straightforward. Keep in mind that blackberry bushes like moist, but not overly wet soil. The type of soil will pretty much dictate water use. Irrigate with a soaker hose or drip irrigation instead of overhead watering, which can cause fruit rot.
Lack of water just prior to and during the harvest season will seriously reduce the crop of fruit your blackberry bushes produce. This will not only affect the current year’s harvest but also the following year’s crop as the water shortage will limit the production of desirable fruiting canes.
During the hottest time of the year, small plants should receive two 6-hour irrigation sessions per week. After the blackberry bushes are established, they are fairly drought-tolerant. Still, water stress will negatively affect the plants’ yield.
Mature plants require more water and more frequent watering than young plants. Most experts recommend you water mature plants about 1 inch of water per week. Try to keep the plants moist at all times without rotting the roots. Twice-per-week watering is recommended during the fruiting stages. When there is extreme heat and wind, give the blackberry bushes more water and more often.
If using drip irrigation, water blackberry bushes 1 to 2 hours every day and longer when the weather is hotter and drier, or when the blackberry fruit is beginning to ripen.