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Why Did My Plant Die?

This is the place to read Ketzel's advice to readers' most harrowing gardening challenges from whitefly eradication to weed killer application, lawn alternatives, and 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 and Cavernous Archive of Enquiry that the Doyenne has already answered. Good clean fun for the whole family.

This week's questions:

  • Dog Behind Bamboo
  • Eel Grass
  • Pruning Elderly Roses
  • Photinia Woes
  • Shaded Tree Roots
  • Bouganvilla
  • Patio Applesauce
  • Amaryllis Seeds
  • Florida Groundcovers

    Dog Behind Bamboo

    Dear Doyenne,

    My husband and I bought a house on a fairly busy street. We have a truly wonderful dog, who gets absolutely BENT out of shape when people, bikes or motorcycles pass in front of our house -- the same pup that loves to french kiss ANYONE if given the opportunity. We thought if we could just block his view a bit, it would ease the situation.

    Everyone warned us about planting bamboo and that it would take over everything and we would rue the day... But, as the rath of raja is still administered on passers-by, we both were hoping for the described out of control growth spurt. We dug healthy bamboo up from our friend's yard a few blocks away and planted it last October. It stayed mostly green for a while and eventually lost its leaves through the winter. Now most all of it is all brown incredibly sad looking twigs sticking up from the ground -- tall twigs, mind you, but leafless for sure. Do you think it's alive?

    Thanks for your help,


    Chances are your bamboo is still alive underground but it doesn't usually start growing here in Portland until really warm weather arrives (that is, consistently above 70°F). You might wait until May or June to make a final assessment. Also, bear in mind that bamboo usually abandons its top canes when moved.

    By the way, people dearly love to rant and scream about the perils of bamboo, but in reality it takes several years for even a running bamboo to take hold. Since it only grows once a year, it can then be easily contained by just simply snapping off the new corms as they emerge and withholding water during the summer. Finally, since bamboo shoots rarely run deeper than 18" underground, an impermeable barrier can be placed to that depth in the future... if it's ever needed.

    By the way, I know you didn't ask, but it sounds like your pup needs a playmate. The County shelter's overflowing with great dogs.

    Best of luck, KL

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    Eel Grass

    Dear Doyenne,
    I bought a home several years ago in which the deluded previous owner planted eel grass around the ornamental ponds. It has since spread, encroached and insinuated itself everywhere. What can I do to kill it. Help!

    Also, I moved here from a lifetime in Southern California where gardening is another very different experience. I have looked for books on gardening in Eastern Washington without luck. All seem to focus on the lusher, much easier Western part of the state. I would appreciate references.


    Oooooh, Eel grass. Well, I do all I can to avoid recommending herbicides, but there are some relatively good ones that are made of potsassium salts or fatty acids, a.k.a. soap. They work best on the first warm days of spring.

    A more labor-intensive measure would be to solarize the soil. This involves putting down two layers of clear plastic (1-4 mm) over the ground where you want to kill the Eel grass. The idea is to cook the plants to death on a hot day. Water the ground first because wet soil conducts heat much better. This process usually takes about 4-6 weeks, and should obviously be done during the hottest weather.

    And of course there is physically pulling it out...

    As far as gardening in eastern Washington, I'd direct you first to Lauren Springer's classic, The Undaunted Gardener. It'll be a great introduction to gardening in the inter-mountain West. Bear in mind you've moved to one of the best rock gardening climates in the world, as well as one of the best places to grow such things as lilacs and fruit trees. So you see? The fun's just begun.

    Good luck, KL

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    Pruning Elderly Roses

    Dear Doyenne,
    I live in Ft. Lauderdale and have just inherited from an elderly neighbor, 3 of his also elderly rose bushes. After letting them acclimate to their new spots in my garden, I attempted to prune some of the old dead wood from them. I see now that each prune has died off even further back along the stem, even killing some healthy new growth. I sealed the fresh cuts as suggested in the rose books but the areas below the cuts have blackened perhaps 6-10 inches below.

    Thank you, Gail

    I suggest you check the blackened canes to see if they are hollow or swollen -- both signs of borers. In any case, prune well below the blackened parts and check to see if the pith in the cane is green (brown is a sign to keep on cutting). To discourage more borers from laying eggs, use waterproof wood glue on the cuts. After that, let's leave the bushes alone for a year or two to let them fully acclimate to your garden. It sounds to me like they are fussing at you because they were moved. Let's hope I'm right!

    Best, KL

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    Photinia Woes

    Dear Doyenne,
    We live in the suburbs of Seattle. This year has been unusually dry, but nonetheless, our Photinia (frazeri I think) is showing excessive amounts of black spots on the leaves. The new red growth seems to be doing fine, but I would like to know what to do about this "black spot". It really looks bad.

    Thanks, Emery

    Unfortunately, once photinia gets blackspot, it can be very difficult to eradicate. The best advice is not always the simplest:

    1. Remove and rake up all leaves that have the blackspot. Do not put them in the compost, put them in the trash. Be diligent about this as new leaves become infected and drop.

    2. Mulch the base of the shrub with good organic compost and fertilize it with a healthy dose of cottonseed meal.

    3. Keep the shrub well-watered during the driest months -- a soaker hose is easiest.

    4. You can try spraying a fungicide such as sulfur but this is only feasible if the plant or hedge is very small.

    Finally, since photinia is very prone to diseases (it's in the rose family, need I say more?), you might consider replacing it with something like osmanthus (e.g., Osmanthus heterophyllus), or if you love that new red foliage, the native huckleberry, Vaccinium ovatum. Both are evergreen shrubs that are not prone to disease.

    Best of luck, KL

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    Shaded Tree Roots

    Dear Doyenne,
    What do I do in a spot where everything dies? The area is underneath some very large Eastern Hemlock (I think) trees. I first planted periwinkle (approx 100 plants) some took where there was more sun, but most did not.

    About 3-4 years ago, I planted Lamium (pink...) and for 2 years they flourished and were beautiful, flowering heavily in the Spring. For the last 2 years, most have died off. I tried some Lamium (White Nancy) last year and they mostly did not make it. I have used fungicide to no avail. I added lime last year. I fertilized last fall with organic mushroom soil. I do not know what to try this spring. Much of the area is bare except for some Periwinkle and few Lamium.

    Thanks, Joan

    Sounds like you're dealing with the double whammy of shade and competitive tree roots. Your best bet is to try something that can outcompete both. I can't believe I'm suggesting this thug of a plant, but how about Aegopodium podagraria 'Variegatum', variegated bishop's weed? Then there's Convallaria, lily of the valley (which also comes variegated but is still too expensive to experiment with) and Arum italicum 'Pictum', a weed in my part of the world. A mixture of all three? Anyway, it's a place to start.

    Best of luck, KL

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    Dear Doyenne,
    I live in Ft. Myers, FL and I want to use bouganvilla to hide a chicken coop. I need to hide an area approximately 30 ft. long Can you tell me how many plants I will need, best time to plant, and any special care that I should take?

    Thank You, Tony

    You can plant bouganvilla anytime in your area. I'd use 6 plants from five-gallon containers planted 5 feet apart (if you use one-gallon plants, set them as closely as 2 feet apart).

    The most important thing to remember about planting bouganvilla is that the plant has incredibly sensitive roots. Any ripping, even a hard jarring of these roots can cause fatal damage. When you plant, cut the bottom off of the pot and insert it (pot and all) into the soil. At this point you can also, very gently, remove the rest of the pot by cutting down the sides.

    The good news is that bouganvilla requires no special care in your area, though you should keep it well watered until you see growth beginning.

    One last tip, only buy plants grown in hard containers. Grow bags are a recipe for disaster.

    Be careful out there! KL

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    Patio Applesauce

    Dear Doyenne,
    Hi! We inherited someone elses garden when we bought our house. The previous owners thought it was a great idea to plant an apple tree directly over a brick patio. Between the fallen apples, and the squirrels dropping apple peels on our heads, it is not a good idea! I can't prune back enough branches to prevent fall and peelings. I would like to use the stuff that is used on olive trees to stop fruit from setting. How horrible a chemical is this and how harmful to insects, birds, squirrels is this. There is plenty for the squirrels to eat in this neighborhood. Any other alternatives? Thanks for your help,

    Robin - Ann Arbor

    I empathize; apples spread over brick are not pretty, and never will be. Consequently, before fooling around with chemicals, you might consider chopping the tree down and planting something choice in its stead. There are lots of lovely options that would do wonders for your patio. Of course a less satisfying option would be to shake the branches when the apples are ripe to get them down all at once, but my hunch is you won't fall for that :} Frankly, anything is better than using chemicals to stop a tree from doing what it does naturally. Really, it's a simple case of right plant, wrong place.

    Best, KL

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    Amaryllis Seeds

    Dear Doyenne,
    Hi Ketz! I've long been a fan of your segments on NPR. I live in Washington DC and am an avid gardner. During winter I enjoy lots of indoor gardening and this year grew a lovely crop of amaryllis, with showy red flowers (red lion variety, I believe.)

    Anyway, during their blossoming, I experimented with cross-fertilizing the blooms, and after the blooms wilted, was rewarded with striking seed pods. Really huge, fertile-looking things, they swelled and now have split open to reveal rows of brown, papery disks with thickenings in the center. I guess these are seeds and would like to experiment with growing amaryllis bulbs from them. Is this possible? I know they're semi-tropical and will need to be indoors all winter, but maybe I can have my own crop of amaryllis bulbs in a few years to yield those amazing flowers.

    Another associated question: I realize I have probably caused the original bulbs themselves to suffer in order to produce the seeds. Now that the seed heads are mature, can I trim them off and just keep the bulbs fed and in the sun all summer, to help replenish the stores of energy in them that enables them to produce flowers in the winter?

    Thanks for your expertise. Take care.


    Yes, you can easily raise Amaryllis to blooming size from seed, and it'll take about 3-5 years depending on the variety. Sow them in pots in regular potting soil as soon as all danger of frost has past and the night-time lows are consistently above 60°F, then leave the pots out in the full sun and water whenever they become dry. You should see seedlings in 3-4 weeks: they'll appear as small grass-like leaves. When they are about 4" tall separate them out into individual pots. Then, in the fall, let them go dormant by withholding water and before winter, move them in to a frost free place. Again, they can be moved outside when all danger of frost has passed. No doubt, you'll end up with some interesting crosses.

    As for the parent bulbs, you're right, they may have expended a lot of energy to form the seed pods. Just keep them well watered and give 'em an occasional dose of high phosphorous liquid fertilizer until the hottest part of the summer when they will go dormant. If they don't go dormant, witholding water will cause this to happen artificially.

    Sounds like you're having a blast, keep it up, girl! KL

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    Florida Groundcovers

    Dear Doyenne,
    We live in Jacksonville, Florida and are having problems with our grass. The area where we live has a lot of sand instead of good dirt and we seem only to be able to grow weeds, especially dollar weed, no matter how much Weed and Feed we put out. We have tilled the yard twice already and got the roots out and put sod down, but every year we have to do the same thing. We have a big back yard with several pine trees in the back and "dessert grass" throughout the rest. I would like to create a beautiful garden of some sort with minimal upkeep since my husband and I both have busy schedules. Could you advise us?

    Thank you very much, Mrs. O'Neal

    Mrs. O'Neal,
    Have you considered trying a ground cover instead of lawn? Especially if you wish to have a lower maintenance landscape, putting in ground cover or paving will cut down on what you have to mow. It sounds like your back yard is a good candidate for lots of paving and a few plantings.

    Since I don't know whether your yard is shady or sunny, I'll suggest some plants for both places. In sun, a good, fast-covering lawn substitute is Mazus reptans or Sedum acre. One plant will cover and area about 9 square feet in a single growing season -- as long as it gets sun and plenty of water.

    In shade, you might try the native pachysandra, violets, or a very low-growing mondo grass called Ophiopogon japonicus 'Nana' or 'Kyoto'. This mondo grass looks very much like a dark green grass, but is evergreen and a member of the lily family. Also, ferns make great groundcover in places you won't walk.

    Incidentally, for future reference tilling is a great way to make weeds!

    Good luck, Miss Ketzel

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