Wednesday, April 21, 2010

Blueberry Blossoms

Edited to add: I can't believe I forgot to mention coffee grounds! They're a great source of nitrogen AND they help acidify the soil - so a perfect soil amendment for blueberries. I only learned this late last summer, so just recently started using coffee grounds. If you don't drink coffee yourself, you can usually get free used coffee grounds from places like Starbucks. They give them away for compost. Another way to minimize your purchased inputs.

Aren’t these gorgeous? I am soooo looking forward to harvesting our first crop of blueberries this year. We planted two Dwarf Northblue (one pictured above) and one Northland (a “half-high” cultivar developed from a cross between a high bush and low bush blueberry) in the spring of 2008. The Northblue was developed at the University of Minnesota and the Northland at the University of Michigan, so they are hardy enough to withstand our Wisconsin winters. (You need two cultivars for good pollination.)

According to the labels that came with the shrubs, the Northland will grow to be about 3-4 feet tall and, when mature, will produce about 20 pounds of medium to small fruit. The two Northblue are smaller; when mature, they’ll be about 20-30 inches tall and produce 3-7 pounds of large berries.

Gardening authorities advise removing the flowers from the shrubs the first two years to promote foliar and root development. I found this very difficult the first year. The tiny shrubs developed beautifully and produced blossoms almost immediately – as you can see in the photo below. I felt like I was practically desecrating the plant – and more importantly, depriving myself of some tasty fruit! The promise in the literature that removing blossoms in the early years will produce better harvests in later years was only thing motivating me to comply with the rule.

It was a lot easier to pull off the blossoms last year because I could see that something was not quite right with the shrubs and I wanted them healthy before they went into fruit production. The leaves were paler than they should be and growth appeared to be slower than normal. I had a soil test done, expecting to find that the pH was too high. That was true – although it was close. But I was surprised to learn that the soil was very low in nitrogen.

Rick built beautiful two-tiered raised beds for our shrubs because blueberries need acidic soil (pH 4-5.5) and the soil here is very alkaline. With raised beds I thought I could better control the soil pH. (R
esearch at Ohio State University found that blueberry yields in raised beds were comparable to those planted in flat soil.) Following recommendations in a University of Iowa publication, I included a lot of peat in the soil mix. I later learned that peat has little to no nutrient value. So although I nearly achieved proper pH, the poor things were starved of nitrogen!

I amended with compost and chicken manure. I also switched to using pine needles to acidify the soil. In addition to the peat, I had added soil sulfur, but the yellow flakes never seemed to dissolve. Even when I had watered well, or we had a heavy rain, I’d find undissolved flakes in the soil. Someone recommended pine needles to me and I liked that idea. These are abundant around here, so I can minimize purchased inputs by using what’s available for free.

(Interestingly, Ruth Stout claimed (in her No-Work Garden Book (1971)) that once she built up her soil with organic matter, like hay, she found she didn’t need to pay attention to soil pH. Following Stout, my goal now is to prioritize soil building over pH – although I will continue to use pine needles.)

As with other perennial food crops, berry bushes are great for a Backyard Nest Egg. Once they’re established, you can harvest fruit for many years. They’re extraordinarily nutritious, with the
highest antioxidant capacity of all fresh fruit. Blueberries are one of the foods recommended to retard aging, preserve vision, and protect against heart disease. I just like to eat them – in muffins, pancakes, or most often, in yogurt. When we lived in Washington state many years ago, some friends showed us where to pick berries for free. We ate them fresh, baked them in pies, made jam, and froze many to last throughout the winter.

Last year I must have missed a few blossoms, because I found a couple of berries on one shrub that summer. They were delicious. If this year’s crop is just as good, we are in for a treat!

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