Climax Blueberries are in a group called “rabbit eye” blueberries. They are a good choice for warmer zones (USDA Hardiness Zones 8-10) with a chill hours rating of 450, which drives their flowering habit. A ‘chill hour’ is one hour under 45oF. In warmer climates, this means they will be less subject to early frost which will kill the blooms and subsequently, not bear fruit. All blueberries require cross-pollination to bear fruit, so plant in close proximity with other blueberry plants with similar, slightly earlier, or slightly later bloom times. Two plants are all it takes, but we recommend at least three, and preferably 2-3 groups of 3 rabbit eye type berries. Climax and other rabbit eye blueberries will grow taller than their highbush relatives of the north.
Like all blueberries, Climax is a slow grower, so patience is truly a virtue.
Seasonal, Location, and Exposure Considerations:
Blueberries will thrive in full sun throughout the day. Avoid planting against east shading tree lines or buildings. The plant will ‘reach’ for the sun as it goes by during the day, causing them to bend their branches. Choose a south, north, or east facing aspect for best results.
Soil Preferences
Climax, and all blueberries must have a low pH. Ideal range is 4.5-5.5. While they do not do well in waterlogged soils, they will require a fairly consistent supply of moisture. The ideal site will have good drainage, but good moisture holding capacity. Mulching is a good idea, especially in drier sites. They are tolerant to most any combination of soil textures, as long as these criteria can be met.
Planting and Care – Container Grown or in Pots
You can grow Climax berries in containers, as long as you remember a few basic requirements. First, remember they will grow taller than their highbush and certainly their lowbush relatives that are more suited to cooler climates, so you want to allow for their fibrous roots with plenty of pot space. Second, you must provide for their acid loving nature with a soil mix that is low in pH. Azalea mixes are your best choice.
Choose a large pot. They have fibrous, relatively shallow roots, so give them plenty of room in which to grow. Your pot should be a full size larger than the container the plant came in. A good size to start with should be at least 18” wide.
Always choose a planter that has drain holes in the bottom so as to avoid a waterlogged condition. Ideally, a pot that drains through well, but that you water often to keep the roots in a moderately moist environment, works best. Don’t be afraid to mulch your pots as it will help in retaining moisture close to the surface where the roots can access it.
When planting in pots, plant to the same soil level as the container your plant came in. Do not bury the crown of the blueberry plant. Gently spread the roots if bound in the pot and spread your soil over and under the roots. Fill the pot halfway, water, let the water drain, then finish backfilling and water again. Monitor the moisture in the soil with your finger to make sure it does not dry out. You should maintain good moisture as the plant establishes itself to remove any remaining air pockets and have a moist soil surrounding all the roots.
Newly planted blueberries don’t require fertilizer. Once well established, blueberries only need nitrogen applied in the spring. Use only fertilizers designed for acid-loving plants. Ammonium Sulfate (21-0-0) in the spring is a good choice. Never use nitrate or urea based nitrogen sources. A good guide is about 1.0 oz of 21-0-0 per plant per year of growth, not to exceed 8 oz for a plant older than 8 years. If complete analysis fertilizers are applied, use only those designed for acid-lovers.
If growing rabbit eye blueberries in colder climates, you will need to mimic temperatures common to the zones in which they grow best (8-10).
Planting and Care – Outdoor Growing in the Garden
Climax Blueberries will thrive in an open yard. As long as you give them full sun exposure, provide for soil acidity requirements and soil drainage/moisture as recommended above, they’ll provide years of beautiful blooms and delicious fruit.
The most common mistake with blueberries is to plant them in too alkaline a soil. If your soil is not between 4.5-5.5, you will have a never-ending battle on your hands. pH is not adjusted in existing soil very quickly. If the soil around the plant is at a high pH, replace the entire anticipated rooting zone with acidic soil.
Mix sphagnum peat with the soil you dig for your hole at a 1:1 ratio. Sphagnum is an acidic form of peat moss. If your soil is near the high end of the pH range, use more sphagnum; and add sulfur to the soil around the planting area deeply and blended well with the soil if possible. Monitor pH every year in these types of soil situations.
It’s best to plant your Climax blueberries in the spring. Dig your hole 2-3 times as wide, and a little deeper than the pot you are receiving them in. Work up the soil in the bottom of the hole, blending some sphagnum with it. Plant to about the same level as the container, or a little above the soil level, so as to provide for settling of the plant. Backfill about half way, water, let the water settle, then finish backfilling. Water generously and water often as the plants establish in the first year while remembering to not drown them.
Watering
Blueberries require close attention to soil moisture due to their fibrous, shallow root systems. Young plants are especially susceptible to drying out, and close attention should be paid to make sure they have a nice moist environment. Use well-rotted mulches for blueberries if possible. Because they are sensitive to nitrate-nitrogen, composts derived from animal manures should not be used. The same is as, or more important with dried or fresh manures.
Fertilizing
Blueberries not only don’t require much fertilizer, but they may be damaged by too much. It is not recommended to fertilize them in the first year; and only modestly in subsequent years using Ammonium Sulfate (21-0-0) or acid plant food. As noted above, about 1.0 oz per plant per year of growth, not to exceed 8.0 oz. Split applications are ok, though not necessary.
Some organic forms of fertilizers acceptable for blueberries include blood meal, or cottonseed meal.
Weed, Insects, and Diseases
Weed control for blueberries is important especially young plantings. Sod and weeds will rob them of all important moisture. Create a weed free area well around the perimeter of your plant prior to planting, then mulch well afterwards. Shallow cultivation should be avoided. Other than weeds, the only other ‘pests’ are birds. Birds will strip your plants just before you’re ready to pick the fruit, so plan to use netting to protect the plants.
Pruning and Training
Blueberries do not require pruning until they are actively growing. Other than removing dead and diseased shoots (which is very important), you’ll not need to prune until you have a few years of cane growth. You’ll want to prune so as to have 5-8 main canes arising from the base of the plant. A good guide is to remove ‘dead’ growth; ‘old’ growth (3 years or more); and ‘low’ growth, so as to encourage an open, tall growing bush. Eventually, you’ll want to ‘top’ your bushes, but cut close to the stem and remove entire branches at a time rather than shearing or shaping. Prune branches that are spreading the bush out too much as they will bend and bow away from the plant, causing splits and problems in the wind or from physical injury. Prune only when dormant (other than when removing dead shoots)
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