Blueberries can be propagated very easily from seeds. They do best if they are started in the months of January and February, however, they will germinate anytime of the year if they receive enough light and heat. To achieve the best results, plant stratified seed from a reputable dealer, like Honest Seed Co. You should see nearly 100% germination. Plant the seed in a flat or bed of pre-moistened Canadian Sphagnum Peat Moss. The peat moss should be two to three inches deep. Sprinkle the seed evenly over the top of the peat moss and gently cover the seed. The seed must be very near the surface, no more than 1/8 to 1/4 inch deep. Keep the peat moss moist. Place the flat or bed in a warm location. A temperature of 70 to 80 degrees is optimal. With this moist condition you may have some trouble with fungus at the surface of the soil. It is advisable to keep a small spray bottle of fungus spray handy to give them a little spray every 7 to 10 days to protect the seeds. Most any fungus spray for fruit should work.
Blueberry seeds are slow to germinate. The first seed will come to life in about four weeks, and most will germinate over the next couple of months. The new plants will be very tiny and fragile. Leave the plants in the flat or bed until they are 2-3 inches tall, then remove and separate them being very careful not to damage the roots. Pot each individual plant in a container 3-4 inches in diameter using only Canadian Sphagnum Peat Moss, again keep the soil moist. Wait about 3 weeks to begin fertilizing. Fertilizing any earlier than this could burn your plant. Use a gentle fertilizer at half-strength. Be very careful especially the first year to keep the plants well-watered and fertilized. Keep the plants in the pots until they are around 8 inches tall, then repot them into a larger size pot such as a one (1) gallon container. Grow the plants/bushes until they are 12 – 18 inches tall before transplanting into the field/yard. It is best to transplant in the fall after the plant has gone dormant. Many will bloom and have berries within 2 years. It will take the plant around 7 years to reach maturity and full production, however you can expect fruit in as little as 2 years from when the seed was sown.
When Ready for the Ground
Site Selection – Blueberries prefer to be planted in a partially shaded area but can also grow well in full sun. When planting blueberries that will be harvested by hand, the plants should be spaced 4 feet apart in rows, with rows spaced 10 feet apart. A mature high bush blueberry’s size on average is 6 feet tall by 6 feet across. Blueberries require a pH of 4.5 – 5.5. You should test your soil prior to planting. Your local cooperative extension agency can help you get an accurate soil test, specific to blueberries for a reasonable cost. There are also many different pH testing probes and testing kits available for home gardeners.
If your pH is correct – dig a hold large enough to hold 2 -3 gallon of wet peat moss. Mix the wet peat moss half and half with existing soil. This will give your plant an ideal soil of grow in and will lessen or eliminate transplant shock. When you are ready to plant, please inspect the base of the plant right above the root system and notice the change in the stem between it and the root system. This is where you should make your soil line when planting; it need not be exact – but close. It is important to not bury the stem too deep. If you are planting a container–grown plant, the soil in the pot should also be level with the top of the soil line in the ground. You want to cover all the roots with soil, but not bury the stem too deep. After planting your blueberry plants, it is best to mulch around the plant. Hold the mulch back from the base of the bush an inch or two.
If your pH is not correct – Amending the pH of your soil prior to planting is crucial. If your soil pH is too high, granulated sulfur can be used to adjust the pH. A soil test specific for growing blueberries will tell you how much sulfur needs to be applied. You must be very careful when applying sulfur! Too much can harm or kill your plants. Sulfur needs to be applied 60-90 days prior to planting. Otherwise, only a very small amount of can be applied around the plants at a time. Peat Moss is the perfect pH for blueberries, so adding it to your soil is helpful. You will occasionally want to check the pH of the soil in the area in which your blueberry bushes are planted and adjust it as necessary. It is extremely important you have the correct pH or your plants may not thrive.
Watering – Blueberries like moist, well-drained soil. It is very important that you water your blueberry plants regularly, especially the first year and throughout each growing season. It is generally not necessary to water blueberry plants after they go dormant in the fall. Blueberries should be watered often, but over watering for extended period of time may be harmful. As a rule of thumb, if the top inch is damp, you’re ok.
Mulching – Blueberries like to be mulched with just about any type of organic matter. Mulch your blueberries with 2 – 4 inches of wood chips, pine bark mulch or needles, peat moss, saw-dust, or decomposed leaves to help retain moisture. Hold the mulch back from the base of the bush an inch or two.
Fertilizing – Blueberry plants will grow better if you fertilize them. Blueberries are acid loving plants, so generally any fertilizer recommended for rhododendrons or azaleas will work well. For a home-owner patch, we often recommend an organic feed product for acid loving plants. Neptune’s Harvest or AG Grand are two organic fertilizers that work well. Always follow the instructions on the label.
Pruning – Pruning may be necessary to remove dead or broken stems as your plants grow. As your blueberry bushes mature, annual pruning to remove the oldest canes will increase your plants vigor and help them stay productive. Pruning blueberry plants encourages new growth. Each cane reaches its optimal fruit production when it is 3 – 7 years old. Starting when the plants are around 7 years old, you should start taking out 1 – 3 of the oldest canes per year. Generally, a mature blueberry bush can be pruned back 15% without decreasing the quantity of fruit you harvest, while maintaining the longevity of the plant. Pruning can be done anytime after the fruit harvest and throughout the fall and winter. General Information – Blueberries are shallow rooted and should not be tilled. Keep the area around the bushes mulched and mowed for attractive appearance and ease of picking. Blueberries are attractive plants with beautiful bell-shaped flowers in the spring that turn into large cluster of delicious blueberries in June and July. Blueberries have bright green foliage in the summer that turns to brilliant shades of orange and red in the fall. Blueberries make nice hedges, landscape groups and backyard gardens. Highly profitable for commercial growers, they take 5 – 7 years after planting to reach full production, though you can expect fruit in as little as 2 years.