I have an uncommon maple (Acer ukuruduense) that I planted two years ago, and which one year ago started sending out long stems from the base, so that now it has a vase shape. One month ago the main (original) stem turned black almost to the ground (the bottom two feet or so are still green), and all its leaves turned brown and fell off. Some of the buds still seem viable, but it seems to be dying at the tips. The rest of the plant is so far showing no signs of trouble. I have not been able to figure out what is going on.
Questions:
1. What is causing this?
2. What, if anything, did I do wrong, and what can I do differently?
3. Might this problem spread to other trees: I have several other small maples in the vicinity.
Other information: The tree is so far just surrounded by bare dirt. This year I watered it frequently with a soaker hose throughout the summer, but last year I was not watering it regularly. It is in full sun, which it is supposed to like.
I am having trouble growing Silene (do not know the species). It has magenta flowers with notched petals on two foot stems and hairy basal foliage. I have killed four plants that were planted in four different locations. I am able to keep hundreds of other plants alive in my garden, but not this one! It flowers profusely from mid April through July. Then the leaves start wilting, and before long, it is dead. The only thing I can think of is that it needs superior drainage. Could I be overwatering it?
You may have one of the annual types of Silene, which die after setting seed. It is really hard to know for sure since there are over 500 species. You may be able to identify your Silene in the book Lychnis and Silene in the Garden, by J.L. Jones, 1999.
There are some magenta-colored species of Silene with notched petals (Silene dioica and Silene hookeri for example), as you describe. These are alpine or rock garden plants that prefer well-drained conditions and do not like highly acidic soil. It is certainly possible that you have overwatered or that the soil in which they are planted doesn’t drain sharply enough or is too acidic.
My question is about Oplopanax horridus. I planted one last winter in deep shade. It has lost its leaves and appears to have gone dormant. 1) Does devil’s club go dormant in the winter? 2) If not, then could it come back with watering in the winter climate or am I better to rip it out and put in another one? 3) How frequently should devil’s club be watered in a normal summer and assuming good loam soil?
Devil’s club does lose its leaves in the winter. Quoting from the source cited below, it is hardy down to at least 5 degrees F, although the young growth is likely to be cut back by spring frosts…On cool moist soils, it forms tall, impenetrable thickets…Plant in sun or part-shade.
(Source: The New Royal Horticulture Society Dictionary of Gardening, Vol.3, 1992, p. 378)
Additionally, devil’s club “grows in well-drained to poorly drained soils with sandy, silty, or loamy textures,” which indicates that it will appreciate regular watering that ensures moist soil in the summer.
(Source: Propagation of Pacific Northwest Native Plants, R. Rose, et al, 1998, p. 129)
![[Pistacia] cover](https://depts.washington.edu/hortlib/graphix/Pistacia.jpg)
Can you tell me the botanical name of the tree that produces these oil-rich turquoise lentil-sized seeds? The trees grow in Amadiya, on a high plateau in Northern Iraq, near the border with Turkey. I grew up snacking on the seeds, and I know the Neo-Aramaic and Arabic name (butma or butum) for it, but not the scientific name.
The tree is a species of Pistacia, most likely Pistacia atlantica ssp. (subspecies) kurdica. There are various English common names for the tree, including terebinth, Persian turpentine tree, and Mount Atlas mastic tree. There is a documented population of this subspecies of Pistacia growing in the town of Amadiya, Iraq. (It does well on steep, dry slopes in high elevations.) These trees are often found growing in association with oak and walnut trees. (This document uses the synonym, Pistacia eurycarpa).
According to Avinoam Danin’s Plant Stories on Flora of Israel Online, only female trees of this dioecious tree produce fruits which are red when young, turning turquoise once successfully pollinated. “When the thin skin is removed the thin but hard brownish stone is reached. When the seed is opened, its green food reservoir is seen. In color it resembles the seed inside the pistachio nut. […] The common name in Arabic for three of the species known in our area is ‘butum.’ This name has preserved the ancient Talmudic name ‘botnim’ or ‘botnah.’ The scientific name Pistacia is also a derivative of a vernacular name [used in Iran].” Danin mentions that the fruits are gathered in fall, dried, and sold in spice shops in Israel. They are also pulverized and used to flavor special sweet cakes.
The tree has a long history in the Middle East, where it can be traced back to the Hebrew bible, and to stone steles describing Mesopotamian gardens and palaces.
Some sources, such as this information from University of British Columbia Botanical Garden, say the fruit of Pistacia atlantica is not eaten “directly” (because it tastes of turpentine to some palates), but taste is subjective and varies in different cultures.
There are many medicinal and ethnobotanical uses of this plant’s fruit and resin.
I have planted petunias over tulip bulbs. Is that o.k., and also, how and when can I fertilize tulips this fall?
Your idea of planting a later blooming plant over the tulips is just fine. It will conceal the dying foliage nicely. According to The Plant Care Manual by Stefan Buczacki (Crown,1993), the time to fertilize tulips–if you need to fertilize them at all–is early spring. They can be mulched (with compost, for example) in early fall and spring, and given liquid feed 2-3 times after blooming and while still in full leaf.
The Brooklyn Botanic Garden’s Spring-Blooming Bulbs (2002) gives the following general advice:
“Most bulbs do better with regular fertilizing, and bulb fertilizer is one good choice. Some gardeners prefer to use bone meal (though the way it is processed today saps most of its nutrients) or rock phosphate. Even better is a healthy dose of compost–in fact, if you regularly improve the overall quality of your soil with compost and other organic amendments, you don’t have to provide much fertilizer for most bulbs. Mix compost or fertilizer into the soil when you’re planting or top-dress, following label directions. to help boost the bulbs for next year’s bloom, you can also top-dress the soil in spring after blooming. Remember to work any fertilizers well into the soil, and avoid high-nitrogen fertilizers (like lawn fertilizer).”
You may not need to fertilize your tulips if they are the showy varieties (the ones that don’t come back year after year in the garden). Seattle-area gardening expert Ciscoe Morris says the following:
“Don’t fertilize spring-blooming bulbs if you’re going to replace them next fall. Most books recommend adding bone meal and fertilizer whenever you plant spring-blooming bulbs. That’s only necessary if the bulbs you’re planting are the kind that tend to naturalize and return to bloom every spring for years to come. Those bulbs not only need fertilizing at planting time, but also should be fed every spring thereafter. On the other hand, most of the big, showy tulips are ill-suited for our rainy cold winters and rarely perform well the second year. If, like most of us, you treat them as annuals and replace the bulbs every year, don’t waste time and money fertilizing them. These bulbs already contain everything they need to grow and bloom, and as long as the bulbs don’t rot as the result of poor drainage, and nothing eats them, they’ll put on a great display without the addition of nutrients.”
My onions are forming flower heads. Should I pinch these off or leave them alone? Will I still be able to harvest onions?
Onions that are forming flowers are said to be bolting. This might be due to the fairly cool weather we’ve had. Here is additional information from Iowa State University.
Excerpt:
“Onions will occasionally bolt or produce a flower stalk. Onions bolt as a reaction to cold weather stress. Temperatures under 45 degrees F may cause the onion to bolt when the plant has five or more leaves. Some onions are more or less susceptible to bolting than others and the process is not completely understood. Unfortunately once the onion does bolt, the quality of the onion bulb deteriorates rapidly and it should be harvested and eaten as quickly as possible.”
This community garden page has general information on the phenomenon of bolting. Early planting, mulching, avoiding overfertilizing, and providing consistent watering will all help prevent bolting. Onions respond to cool springs followed by warm weather by bolting. An Oregon State resource on growing onions describes the onion’s development as follows:
“All onions are biennial, meaning that they normally take two years to grow from seed, flower and set seed again.
Onions first grow ‘vegetatively,’ forming roots, leaves and other plant growth. Once these basics are established, the bulb, the part that is generally known as an onion, forms when the day and night lengths reach the proper length for each particular type of onion.
Once an onion bulb forms, there are enough nutrients stored for flowering, or ‘bolting,’ usually occurring during the second year of an onion’s two-year life. Flower formation usually ruins the bulb for harvest as an onion, as the resources of the bulb usually are absorbed to send up the flowering stem.”
You may find this guide to growing onions from the Center for Agroecology at U.C. Santa Cruz helpful. It also mentions temperature in relation to bolting.
We live in a heavily treed (fir and cedar mostly) condominium complex. Our shrubs are sprayed twice a year by a professional spraying company to protect against fungus and other problems. We are thinking of spraying every other year to save on expenses.
Would we be jeopardizing the health of our shrubs and small cherry trees by doing so?
Unless your shrubs and trees have a history of trouble with diseases, I can’t think of any reason they should be sprayed at all. Even if the plants were susceptible to disease, a more sustainable approach than annually applying fungicides and other pesticides would be to select disease-resistant plants that will thrive in your garden’s conditions without that sort of intervention.
Spraying, depending on what is being sprayed, can be a hazard to human health and the environment. You may be able to stop your spraying program entirely by instituting good garden practices, like cleaning up debris and providing good air circulation around the trees, and avoiding overhead irrigation.
Examples of nonchemical ways to manage fungal problems that may affect ornamental cherry are provided below, from Washington State University Extension’s HortSense website:
“Brown rot is a fungal disease which initially infects the flowers. The petals turn light brown, develop water-soaked spots and may have tan or grayish areas of fungal spores. Infected flowers often remain attached to the plant, spreading the disease to small twigs and branches. Infected twigs and branches are often observed in the summer as flagged, dead leaves and twigs. Infected branches develop cankers which may produce gumming (leaking sap) or may girdle and kill the branch. Most brown rot cankers develop with a dead twig at the center where the initial branch infection occurred. Fruit can also be infected, dry out, and hang in the tree. Tan or gray fungal spores may be found on infected blossoms, fruit, or twig cankers. Ornamental and fruiting stone fruit trees are affected.
Select Non-chemical Management Options as Your First Choice!!
- Avoid wounding trees.
- Clean up and destroy fallen flowers and other debris beneath trees.
- Remove and destroy all infected twigs and branches during the summer, making pruning cuts well below infected tissues.”
Similarly, here are their recommendations for managing Coryneum blight or shothole:
- Avoid overhead watering, as leaves must be moist for infection to occur.
- Prune and destroy dead buds and cankered twigs if present.
- Rake and destroy infected leaves.
Again, for cherry leaf spot:
- Avoid overhead watering. If overhead irrigation is necessary, limit it to times when foliage can dry quickly.
- Rake and destroy all fallen leaves and debris under trees.
- Space plantings and prune to provide good air circulation.
I want to plant a Callistemon variety with yellow flowers in my garden, but will it still be attractive to hummingbirds? I know they like the red-flowered ones.
I can’t say with complete certainty, and it may take a little while for hummingbirds to discover this new addition to your garden, but according to the book Hummingbird Gardens by Nancy Newfield and Barbara Nielsen (Chapters, 1996), the genus Callistemon in general is attractive to hummingbirds. The authors quote a California gardener named Charlene Butler, who grows red, pink, and white-flowered varieties which “have flushes of bloom, and when they’re in bloom the hummingbirds go nuts.”
Just as insurance, you could plant perennials (such as Crocosmia ‘Lucifer,’ Salvia, Penstemon) which are known attractants near the Callistemon.
This fall, the evergreen tree (needles, sort of bluish in color) in front of my house has been driving me crazy. It’s dropping tons of soft, yellowy, pod-like things and when people walk into the house, they track in this yellow pollen and it stains the carpets. First, what kind of tree does this, and second, is it on some kind of cycle? Will it stop dropping these things soon?
Without seeing the tree, my best guess is that it is a type of Cedrus, possibly Cedrus deodara or Cedrus atlantica. Since it is now October, what you are seeing is the shedding of male catkins or pollen cones. This is a seasonal phenomenon, so it will stop soon. Oregon State University’s Landscape Plants database has some pictures of the cones in fall. Meanwhile, you might want to have a shoes-off policy inside the house, which should cut down on the invasion of pollen.
My canna has a leaf with a set of 9 holes in a straight row, all symmetrical with each hole a bit bigger than the one to its right. Any idea what’s causing this? I must say that we’ve been greatly amused with our yard this summer–it seems like every day there’s some new critter or discovery.
I found the following information in The Gardener’s Guide to Growing Cannas by Ian Cooke (Timber Press, 2001):
“Cannas seem to be particularly attractive to slugs and snails and can be totally devastated by them. Unless you control them, expect young leaves to unfurl with cut patterns like a child’s paper-tearing exercise!” (This is a Britishism for what we think of as papercutting, like paper snowflakes.)
The easiest approach to slug and snail control is to use the newer generation (organic garden-acceptable, but not good to use where runoff will enter lakes and streams) slug baits which are wheat gluten-based pellets with iron phosphate as an active ingredient (such as SlugGo and EscarGo). Be aware, however, that there are reports of dogs eating the bait and developing iron toxicosis.
The safest approach is to use the following non-chemical controls (traps, barriers, natural predators):
Northwest Coalition for Alternatives to Pesticides, click on link to read document.