After spending 2 days at the Pittsburgh "Farm to Table" event recently talking to both experienced and novice gardeners, I now have a new perspective in my own garden. Here is a recent example. Pruning blueberries was not at the top of my early spring 'to do' list, but the weather made me reconsider. A cold wind coming off the lake blustered in the area I'd intended to work in, but it was sunny and milder near the old row of blueberries...so they got my attention.
So what does this have to do with a new perspective on gardening? Well, even though I'd professionally pruned landscape plants for years, I'd never actually pruned a blueberry bush. I found myself looking at a row of about 30 plants, most of which had never been touched. I started to feel a bit intimidated, much like the wanna-be first time gardeners I'd met over the weekend. Where to start? I wanted to improve things, but we'd had a record year of production last year and I knew the pruning I needed to do would remove this year's flower buds.
I gave myself a pep talk. Basically, I reminded myself that I already knew some basics. First off, I knew that pruning for fruit is different from pruning landscape plants. Second, I knew where to find research-based information about pruning almost anything on the web. Finally, I knew I had that "safety net" of blueberries still in the freezer from last year. So what if I pruned too hard. Plus, I'd read the regional Extension bulletins during the winter & knew to completely remove some of the oldest canes. I had shiny new, easy-to-use loppers in hand - - now it was time to get started!
After a few cuts, though, I had the same uncertainties first-time gardeners deal with. The pruning gurus said to take anything older than 5 years as those canes are less productive and to keep a couple of the one, two, three and four year old canes. But how to tell which were the oldest canes? How to tell which shoots were young blueberries & not dogwoods or maples? And most of my plants only had 4 or 5 canes (because they'd never been pruned or fertilized to stimulate new canes) and a couple only had one main trunk! This information was not in the literature, so I had to think for myself. Here's part of my thought process.
- The oldest canes have woody gray bark and are generally largest in diameter near the ground. These are the canes to remove.
- Which young shoots would produce blueberries & which would not? I tried looking at the tips of the older canes, but those were covered in flower buds and looked nothing like the young shoots coming from the ground. Then I thought to look at the bud structure...did blueberries have alternate or opposite buds? (think 'zig zag' for alternate and 'W' for opposite) This doesn't change in appearance between old & young shoots. Lucky for me, blueberries have alternate buds, while the seedlings coming up in the row were opposite. All were quickly dispatched to the growing pile of trimmings.
- Since none of my plants had the ideal 10-15 canes, I had to decide how many to remove. I chose to remove all of the largest canes, even if they may not have been 5 years old. This was not an easy decision, as they had the best flower buds. I decided that generating more new canes for the future would be worth it in the long run, even if that meant a reduced harvest this season. I consoled myself with the knowledge that fewer blueberries meant bigger blueberries, as the root system was still intact and feeding fewer canes.
- As with all woody plants, anything dead or dying was removed.
- What to do about plants with just one trunk? Cut them off at the ground and hope for new shoots or cut above the new shoots growing between the ground and 6 inches up? These new shoots were the diameter of a pencil and Manzanita red in color. I thought about experimenting by cutting one back to just above these shoots and the other one at ground level. I decided not to decide and moved on down the row.
I made it through about half the row that first session. It was time to stand back & look at the larger picture. I saw a row of blueberries that will be much easier to cover with bird netting and some plants that could use a shot in the arm. As a result, I've adjusted my blueberry care plan to include fertilizing with ammonium sulfate in addition to adding sulfur (to keep pH between 4.5 and 5.0 - that's really low.) This will provide nitrogen to stimulate new shoots and will acidify the soil, making the nutrients already present more available to plants that thrive in acid soils.
Finally, since these plants will not receive supplemental water, my seasonal plan includes mulching to conserve moisture critical to production. Lucky for me, the llamas in the barn generate plenty of well-rotted sawdust, an ideal material for blueberries. Looks like my blueberry plan is coming together. If you are considering growing blueberries either for fruit or landscape value, here are links to the same good information I used. Allegheny County Extension Educator Sandy Feather's article "Pruning Blueberry Bushes" http://www.donnan.com/Blueberry.htm and Ohio State University Extension Fact Sheet http://ohioline.osu.edu/hyg-fact/1000/pdf/1422.pdf .
Linda Grotzinger
Before pruning...
Old (gray) and young (red) stems...
After pruning...
