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This is the place to read Ketzel's advice to readers' most harrowing gardening challenges, from whitefly eradication and lawn alternatives to bulb care. No matter where you keep your garden, check out the resources available to you locally. Find a shady spot and maybe a helping hand in the Talking Plants Gardens and Arboretums map of the United States.

Here's the vast Archive of Enquiry that the Doyenne has already answered. Good clean fun for the whole family.

This week's questions:

  • Desert Garden Ideas
  • Thai Pepper Plant
  • Sunflower Seed Hulls
  • Winterizing Banana
  • Under a Walnut Tree
  • A Shade Tree for Annapolis
  • Pruning Wisteria

    Desert Garden Ideas

    Dear Doyenne,
    You've got to help those of us down here in the desert! What can I add to make my little patch of sort-of desert bloom? I need to put in some kind of ground cover -- the left-over Bermuda grass from the last homeowner was virtually ruined by his penchant for raising Dalmatian puppies in the back yard. I'd like some vines to trail over the walls. And what about an acacia tree? Lavender is growing well in one border, and there is great hope that the rosemary will grow this spring. I'm adding some culinary sages near the kitchen, and there're also marjoram, oregano, and some thyme struggling along. These are minor. I need BIG help!


    First let's talk books: Native Plants for Southwestern Landscapes by Judy Mielke, Plants for Dry Climates by Mary Rose Duffield & Warren D. Jones and anything by Mary Irish.

    Some plants I'd grow if I lived in the desert:
    Acacia farnesiana (syn. smallii) - delicious fragrance
    Acacia pravissima - One of my FAVORITE plants
    Acacia willardiana - only if your winter lows are in the upper 20s; white bark

    Other very cool things to try:
    Buddleia murrubiana - orange flowers and gray leaves
    Leucophyllum (Texas Rangers)
    Eriophyllum (Wooly sunflowers)

    For groundcover:
    Baileya multiradiata (Desert marigold) - Tough; nice yellow daisies
    Daleas (Indigo Bush) So many; maybe D. greggii?
    Tequilia greggii - WOW!
    Sphaeralcea ambigua - Apricot Desert Mallow.

    Your cup runneth over!

    Enjoy, KL

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    Thai Red Pepper

    Dear Doyenne,
    I recently purchased a really cute Thai Red Pepper plant at the local health-food store. It's quite beautiful and lacy and already full of little red peppers. Unfortunately, it came with no operating instructions. I know not how much water and light it needs, or when/how to harvest the peppers. Can you help?


    These cute little peppers that are sold as houseplants are kind of a cruel trick. They really need greenhouse conditions. Give the plant as much light as possible and water when dry. Also, make sure that it was grown organically before you harvest the peppers, which can be picked as soon as they are red. Good luck, and manage those expectations!

    Best, KL

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    Sunflower Seed Hulls

    Dear Doyenne,
    Greetings from the Northwoods! We feed the birds a LOT in the winter months and end up with a couple hundred pounds of sunflower seed hulls covering the ground under the feeders. Can we recycle the hulls and use them for a mulch?

    Jo Ann

    Jo Ann,
    Sunflower seed hulls, especially black oil seed, are the most desirable seed for most wild birds beacause they provide the highest nutritional value for heat and energy needed to live. But have you ever noticed that nothing grows underneath the feeder where they are used? That's because sunflower seed hulls contain a growth inhibitor that is toxic to most ornamental plants. So to answer your question, no, do not add these seeds to your compost or use them for mulch where they can interfere with the growth of your landscape plants.

    Best, KL

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    Winterizing Banana

    Dear Doyenne,
    We live in Oklahoma and have several banana plants outside. We are wondering if there is a way to keep the plants outside all year and not have to plant and replant them each year. Our winters are about 25 to 35 degrees at night and I know they will freeze if we just leave them out there. Is there a way we can cover them in the winter time so that they won't freeze?

    You should be able to overwinter your bananas in the ground if you provide them with some protection. In October, cut the banana back to 3' tall. Construct a wire cage around the base and then fill it with dry leaves to about 2'-3'. Then, surround that with a tarp or plastic and surround that with a bungie cord or twine to keep it in place. Remove it after all threats of a hard freeze are past. If you would like to grow a banana that does not require winter protection in your zone check into Musa basjoo, reportedly hardy below zero.

    Best, KL

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    Under a Walnut Tree

    Dear Doyenne,
    There is an area in front of my deck that is partially shaded by a walnut tree. I've planted zoysia grass, but it could not withstand either the shade, the droppings from the tree, or my five (yes, five) dogs. I'm almost willing to plant Bermuda sod, which I hate, to keep from having a year-round mud pit near my house.



    Black walnuts produce a chemical called juglone, which occurs naturally in all parts of the tree, especially in the buds, nut hulls and roots. The leaves and stems contain smaller quantities of juglone, which is leached into the soil after they fall. The highest concentration of juglone occurs in the soil directly under the tree's canopy, but highly sensitive plants may exhibit toxicity symptoms beyond the canopy-drip line. This may be why you are having a hard time gettting anything to grow under your tree (dog traffic doesn't help either). You may want to stick with a ground cover, such as Japanese winter creeper, Euonymus fortunei (though this depends where you live, since it's an invasive plant in some areas of the country). Another option is simply using a woodchip mulch around the tree to keep the mud to a minimum.

    Best, KL

    Web Extra!
    Everything you've ever wanted to know about black walnuts!

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    A Shade Tree for Annapolis

    Dear Doyenne,
    I have a Norway maple in my yard that is about to succumb to sunscald and resultant insect damage. I have a perrenial border on the south side of the tree, about 12 feet away, and I've been hacking away at those invasive roots for long enough. I do want to replace it with another shade tree, though, because it shades the driveway in the summer. My ideal tree is deciduous, deep rooted, with nice fall color, and medium to fast growth rate. Bonus features would be interesting flowers or bark -- no messy fruits, of course. I'd like a tree that's somewhat distinctive for my area and am willing to hunt around for a different and/or larger specimen. Do you have any suggestions? I live in Annapolis, Md. zone 7, with hot, humid summers.



    How about Red Buckeye (Aesculus pavia). This is a native tree with beautiful red flowers that blooms in late April to early May. I once saw a great specimen tree in full bloom in Brookside Garden, Md. so you know it'll work for you. Ultimate height is about 20 to 30 feet.

    Another idea is Magnolia 'Elizabeth'. This is small tree with approximate height of 25 to 35 feet and -- wait for it -- light yellow flowers. Also, it's resistant to frost damage as it blooms in May. A gorgeous plant.

    Finally, consider Betula nigra 'Heritage' (river birch). Doesn't produce showy flowers, but it's an excellent shade tree with tan peeling bark. This is a big, multi-stemmed boy, capable of 40 to 60 feet if given a lot of water.

    Enjoy, KL

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    Pruning Wisteria

    Dear Doyenne,
    How and when should I prune wisteria? How old do the vines have to be before it flowers?



    Since you don't mention whether yours is a young or old plant, I'll start with this: Young wisteria can grow 10 feet in a year and need careful training and pruning to ensure a strong framework. Regular pruning keeps the vine within bounds and promotes better flowering; however, it can take anywhere from 10 to 15 years for a wisteria to reach blooming stage.

    Here are some year-by-year instructions for new vines:

    The first year after planting, in late winter or early spring, cut back the strongest shoot to two-and-a-half-feet above the ground. At the same time cut off all other side shoots. In midwinter of the second year, cut back the central leader to three feet from the topmost lateral shoot. At the same time, shorten all lateral (side branches) to one third of their length. Tie them to their support. Finally, in midwinter of the third year, cut all the horizontal shoots back about a third of their length, cut back the central leader again to within three feet of the uppermost horizontal stem, and shorten lateral shoots by one third.

    For older, established wisteria, summer pruning (July) is best. Winter pruning encourages rampant leaf growth and removes established flower buds. About two months after wisteria leafs out or has bloomed, cut each side shoot back to its sixth leaf (a 10 to 12 inch stub with six leaves). This will help induce them to produce the short spurs that will bear next season's flower clusters.

    Trim lightly again in the winter. Shorten side branches back to the cuts you made in the summer (to 12 inches long). But avoid cutting into the short side branches that will have fat flower buds (if the plant is mature enough to start flowering.) Remove any suckers that appear at the base of the plant.

    That just about covers it. Best, KL

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