Friday, April 29, 2016

X is for xylem

Yay! Here in western New York, gardening season is starting! People are out mowing their lawns and the daffodils are blooming.

This is exciting stuff. I remember starting these blogging challenges on April 1st, wondering when I would be able to go outside and clear out the old gardens and prune the rose bushes. And, then, a few days later, it started to snow! Would winter ever end?

Winter has ended. I'll happily welcome it back in late November. Or, preferably, mid-December. After Thanksgiving and before Christmas. This past Christmas was sadly snow-free. Santa Claus still managed to deliver his gifts to all of the children, despite the lack of snow.

OK, I am delightfully off topic. This post isn't about snow (an evil four-letter word at this time of year) but about plants and gardening. It's a little bit of garden botany.

My X word is xylem. Xylem is vascular tissue in any plant that has a stem, whether it is a flower or a tree. Xylem conducts water and minerals through the plants. Xylem vessels are tubular in shape and they act as a pipeline, from the roots through the stem and into the leaves. When you water your plant or give it plant food, that's how the water and the plant food get from the roots to all parts of the plant. Phloem is the other necessary vascular tissue in the plant. Plants get their nutrients via photosynthesis. They transform light energy, usually from the sun, into nutrients (sucrose) to feed the plant. Phloem vessels are also tubular is shape and they act as a pipeline, from the leaves down to the roots. Both xylem and phloem act to keep the plant nourished and hydrated. 


Anything that interferes with the plant's vascular system (the xylem and the phloem) is very likely to kill the plant. The emerald ash borer, which I described in my trees post, is an example of something that kills by interfering with the ash tree's vascular system. The emerald ash borer is an invasive species in North America. It has no known enemies, unlike in Asia, where its chief enemy is a parasitic wasp.

The emerald ash borer, in its larval state, burrows underneath the bark of the ash tree. It feeds on matter beneath the bark. It eats the phloem, cambium, and sapwood. These insects interfere with the ability of the tree to get water and nutrients and, as a result, the tree dies. The presence of the emerald ash borer is an ecological disaster for North America.

If you have ash trees, contact a reliable tree service and have your trees protected. If your ash trees are already infested, get the tree service to remove the diseased trees. It is OK to mourn a dead tree. It's even more OK to remember a dead tree by planting a new tree, preferably of a different species, in your yard.

Enjoy the sunshine and your gardens and the beautiful colors of the spring flowers.


1 comment:

Alana said...

We have no ash trees in our yard, but there are several in our neighborhood. The elms, the chestnuts, and now this. It's sad.

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