the show

Mushrooms, Lichen, & Other Fungi

air date: January 19, 2013

Where do mushrooms come from and what are they doing in the garden? Ashley McKenzie from the Texas Wild Mushrooming Group notes their beneficial relationship with plants and how to keep it going. On tour, even winter is bountiful in Lynne and Jim Weber’s native habitat garden. Daphne Richards explains why to prune trees in winter. Her pick of the week is evergreen mountain pea, a lush groundcover for shade and sun. Trisha Shirey shows how to cage tomatoes and build trellises for vining vegetables and fruits.

Episode Segments

On Tour

The Weber Native Habitat Garden

In every season, wildlife finds food, shelter and water in Lynne and Jim Weber’s drought-tough National Wildlife Federation Certified Backyard Habitat. Their small front garden hosts seeds, flowers and larval food, even in winter, to welcome native and migratory wildlife. As Texas Master Naturalists and NWF habitat stewards, they published a book, Nature Watch Austin, which tracks plant and wildlife activity in a monthly diary.

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Question of the Week

Why do we prune trees in Winter?

We want to prune trees in winter because this is the least stressful time for the tree.

You can definitely prune woody plants at other times of year, but pruning in winter takes advantage of the tree’s natural growth cycle and encourages faster, more complete healing.

Most of our trees are deciduous, so they are dormant in winter. And even semi-evergreen species like live oaks don’t actively grow when it’s cold out. So their plant sap, which contains water, nutrients and hormones, isn’t actively flowing at this time of year. This means that the cut surface won’t have lots of sap rushing to it, as it would in the spring, which would attract insects and disease spores–which are also more active in warmer weather–to the source of a direct route into their body.

But a bit of sap-flow is actually a very good thing, leading to natural healing of the wound. Shortly after being cut, the tree will start to form callus tissue, which will at first look like a small donut ring, and will eventually, perhaps after many years, grow to cover the entire cut surface.

And because you want a little sap-flow but not too much, the late winter, when plants are still asleep but are getting READY to wake up, is the best time in the plant’s natural growth cycle to take advantage of this strategy.

This is especially true when pruning oak trees, to avoid the possibly of oak wilt, which is insect-vectored. Like most insects, the beetles that vector oak wilt are not active during the winter, so there is very little chance of infection if you prune at this time.

Because of oak wilt, it’s advisable to paint the pruning cuts on oak trees. But this is NOT recommended on other species, since the pruning paint actually inhibits the natural healing process.

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Plant of the Week

Mountain Pea

Mountain Pea

Orbexilum sp.

This evergreen Mexican native plant makes a great groundcover in sunny or even shadier spots in your landscape. The leaves are small and the delicate purple flowers even smaller, but mountain pea creates a nice little thicket and gives a lot of bang for your buck. It's fairly tall for a groundcover, growing to about 2' tall and 3' wide. It does well in bright sun and thrives in part shade. But if planted in too much shade, it will stretch for the sun, making it a little taller and lankier, and will have fewer flowers. This is a great option to plant under large trees where you want to cover the ground in dappled light. Well-drained soil is best. Mountain pea isn't the most drought tolerant, but mine survived the terrible heat and drought of 2010 while being watered only on my legal days, so it does just fine, with a little care.