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Planting Japanese Iris – Pruning Trees

Fox Brook Iris Farm

One of the benefits of the summer garden tour and event season is the chance to meet new people with unique passions and knowledge. When I attended the Western New England Japanese Iris Show in Shelburne Falls at the end of June. I saw exhibition blossoms of beautiful Japanese irises grown by local gardeners, stunning arrangements, and was inspired.

Japanese iris bloom from mid-June into July, coming into flower when the Siberian and then the bearded iris seasons have passed. The blossoms are flatter than bearded irises, but they are certainly just as glamorous, coming in shades of blue, purple, pink, and white with many bi-colors – and they are less trouble than bearded irises.

After I left the Iris Show I drove to the Fox Brook Iris Farm in Colrain which is run by Deborah Wheeler and her son Andrew. Andrew became fascinated by irises in high school, and is currently working on his PhD thesis on viro-genetics which involves the DNA sequencing of plants. This means he will be one of those people who decides that a particular plant has been put in the wrong family, and corrects the error.

When I arrived Andrew was in the middle of the Japanese iris field, a sea of flue and white, ready to dig. It took a while but I finally chose a very frilly white Hakuroko-ten which he dug and wrapped for me in wet newspaper while he explained how to care for it. I said I knew it needed to be in a damp spot. He said, “I think people misunderstand the Japanese iris’s need for water. The do not want to grow in a boggy spot that is always wet. They do need to be kept watered, but the roots need to be able to breathe between waterings.”

He also pointed out that irises are heavy feeders so they should be planted in soil enriched with rotted manure and compost. The soil should not be limed. A soil that is too sweet can eventually kill the iris.

When I asked if irises were attractive to rabbits, who have been giving me so much trouble this year, he said, no. Apparently, animals know that all irises are purgative, and keep well away from them That is why if there are blue flags growing near a pasture stream, they thrive because the cows will not go near them.

I planted my irises instantly when I got home and have been keeping them well watered. I am looking forward to wonderful spring bloom.

I also got to walk across the Bridge of Flowers with Dennis Ryan, an urban forester, Umass faculty member, and friend of the Bridge, to look at the trees. Some of the trees like the flowering cherry are small and will stay small, but some like the flowering crabapples have become quite large.

Ryan explained that it is possible to prune trees, as they grow, to control their size. I am such a timid pruner, but he said that one third of a tree can be pruned away without causing any damage. He showed me where he could prune one of the Bridge’s Rose of Sharons, which is actually a large shrub, but the same rules apply. You can take off a large branch, cutting  back to a branch that is one third the diameter.

Of course he reminded me that trees or shrubs that bloom in mid-summer or later can be pruned in early spring, but spring flowering shrubs like rhododendrons need to be pruned right after they bloom. Close observation will show a gardener that a rhododendron sets buds in the fall. If you prune in the spring, you will cut off all the buds.

If flowering is not an issue, he said that summer was an ideal time for pruning. “Farmers prune their fruit trees in winter because that’s when they have time, but winter pruning causes more suckering. When you are pruning for shaping and control of size you should prune in the summer because there is little likelihood of suckering,” he said.

I put his suggestions to use in my own garden by pruning a weeping birch that has branches dragging on the ground, and also has a dense curtain of graceful branches where I had envisioned a lacier effect.

My huge Mothlight hydrangea, planted next to the birch is in need of pruning to bring the height down. I will do that in the fall after it has bloomed, but I am already looking at the branching patterns to see where I might cut.

I also decided to limb up my gingkos. While I treasure every inch of shade these 13 year old trees supply, the branching begins at about four feet. I’d like to be able to walk below these trees which are at the edge of the bed without bending and crouching.

Limbing up, pruning off the lower branches of a tree, can be desirable when the need is for dappled shade, also sometimes known as high shade. Even sun loving plants don’t mind a couple of hours in the shade if it is not too dense and dark.

Have you met anyone this summer with an interesting passion or useful information? I would be glad to share that with my readers. Just email your comments to commonweeder@gmail.com. ###

Between the Rows   July 14, 2012

1 comment to Planting Japanese Iris – Pruning Trees

  • Good post. I was becoming more and more tempted to get some Japanese iris until I read that it didn’t like alkaline soil. But I will make some time to prune my crabapple.

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