removing burls from trees

I would like to remove a burl from one of my fir trees. Can I do this without causing harm to the tree?

I was unable to find any information on the incidence of burls (lignotubers) on fir trees (Abies), but I did locate information about redwood (Sequoia sempervirens) burls from a version of The Sempervirens Fund website which is no longer available:

About Redwood Burl

by Chris Brinegar, PhD

“The swollen tissue at the base of some redwood trees is commonly known as a “burl” although scientifically it is referred to as a lignotuber (from the Latin for “woody swelling”). All redwoods have lignotuber tissue but not all have large visible burls. Lignotuber tissue is derived from cells that exist in the tree’s seedling stage and then proliferate near the base of the tree as it ages. Buds form within the woody burl and remain dormant until stimulated to grow by damage to the main trunk (usually by fire or logging). The resulting shoots grow rapidly using carbohydrates stored in the surrounding cells and minerals transported through the parent tree’s root system. Lignotubers can also form their own roots.

Lignotubers are responsible for vegetative (clonal) reproduction common in redwoods. Without this mode of propagation, the redwood forest would appear far different than it does currently. The second and third-growth redwoods in our coastal forests were generated vegetatively after 19th and 20th century logging of the original forests. If redwoods were solely dependent on reproduction from seed, their numbers would only be a small fraction of what we see today.

Most people think of burl as the “sliced redwood” sold in gift shops and roadside stands, but they do not realize that many of these burls were obtained illegally. There is a growing black market for burl with much of it coming from unscrupulous dealers who harvest it from healthy redwoods on protected forestland. In some cases, removing burl can kill a tree or, at the very least, deface it and reduce its reproductive potential.

Burls can be planted under the appropriate conditions to allow the shoots to form roots and then grow into trees, but the typical buyer of a redwood burl places it in water, watches the shoots grow, then disposes of it after the shoots die from lack of nutrients. If you are determined to grow a redwood tree we suggest that you purchase a small seed-derived tree from a reputable nursery rather than trying to grow one from a burl that may have been acquired through questionable methods.”

According to the information here, it seems that by removing a burl, you may risk harming or killing the tree. You might want to contact a certified arborist in your area, and ask them what they recommend. Here is a link to the website of the Pacific Northwest chapter of the International Society of Arboriculture, where you can find lists of certified arborists.

removing unwanted bamboo

I recently moved to a property that used to be a bamboo
farm. About 1 acre of bamboo remains. It is of the Henon species and
about 20-25 feet in height and it appears to have some mite infestation.
I want to remove all of the bamboo, and restore the land to native plant
habitat. What is the most economical way to remove bamboo and its root
clumps? I have hand dug (and burned) a lot of bamboo, but frankly feel
overwhelmed by the task at hand because there is still a lot of bamboo on
the property. Any suggestions you can offer would be immensely
appreciated.

The American Bamboo Society website (page now archived) has information on getting rid of
unwanted bamboo, excerpted below. Henon bamboo is a name for a variety of
Phyllostachys nigra, which is a running bamboo.

REMOVING A RUNNING BAMBOO

If new shoots of bamboo are coming up all over your yard, it is a running
bamboo. To get rid of it, there are four steps:

Cut it off.

Cut it down.

Water the area.

Cut it down again.

Cut it off. All of the culms (stalks) of bamboo in a clump or grove
are interconnected underground by rhizomes (underground stems) unless you
have cut them by digging a ditch or cutting a line with a spade. A bamboo
grove is usually one single plant, not a group of plants. Many people
have the impression that every bamboo culm is a separate “tree.”If the bamboo in your yard has come across from your neighbor’s yard,
separate your grove from his by cutting the connecting rhizomes, which
are usually quite shallow. If you don’t, and his part is healthy and
vigorous, the rhizomes in your part will still be supported by the
photosynthesis in the leaves of his part, and your efforts will be in
vain. On the other hand, if you do manage to kill your part with a
herbicide you may also kill his part. Lawsuits or at least hard feelings
can result.Therefore, be sure to isolate the portion you want to keep from the
portion you want to kill. Cutting rhizomes with a spade or a saw will do
the trick if you do it every year. If the growth is old, you may need to
use a mattock or a digging bar the first time. Digging a ditch and
putting in a barrier* is a more permanent solution.

Cut it down.Cut the grove to the ground. All of it. If there is any part you want to
keep, see (1).

Water and fertilize the area, to cause new growth.

Cut it down again. And again.

New shoots will come up from the rhizomes. Break them off or cut them off
with pruning shears. Keep doing this until no more shoots come up. This
will exhaust the energy stored in the rhizomes underground. Without green
leaves to photosynthesize and produce new energy, they will no longer be
able to send up new shoots. The rhizomes will be left behind, but will
rot away.That’s all you need to do. You need a saw, a pair of pruning shears, and
patience, and maybe a spade and/or mattock. The widely advertised
herbicides don’t work well on bamboo, probably because so much of the
plant is underground. Since cutting the bamboo down will do the trick,
and you have to cut the bamboo down anyway to remove it from your yard,
herbicides are a waste of time and money in this case.

The method described above sounds labor–and time–intensive for a large
area like yours. However, if you can cut it all down as close to the
ground as possible, and then repeatedly mow any new growth, you may be
able to kill it. Here is what the USDA recommends:

Eradicating bamboo is accomplished by first removing all top growth, and
then destroying the new shoots as they emerge. If the ground is level and
the canes can be cut off very close to the ground, mowing is the best way
to destroy new shoots. If the ground cannot be mowed, the canes should be
cut down and the area plowed to destroy new shoots as they emerge.
Several plowings or mowings will be necessary, but the rhizome need not
be removed; it will become depleted and die.

This information is from gardening expert Mike McGrath, via a
commercial garden supply business, and there is a possibility that his
suggestions of sheet mulching the area (also labor-intensive if you have
an acre to deal with) or using high-strength vinegar-based products (use
extreme caution with these, even though they are ‘natural,’ as they are
still quite hazardous) might help.

on organic fertilizers and soil amendments

I was wondering if you could provide me with a more or less exhaustive list of organic fertilizers and soil amendments, their nutrient profile, and what they are good for, etc.

When you say ‘organic’ fertilizer and soil amendments, do you mean those
items which are allowed under current organic regulations? I ask because
there is considerable difference of opinion over what is meant by the
word ‘organic’ in this context. Sewage sludge which contains heavy
metals could be said to be organically derived, but might not pass muster
in an organic garden, for example.

If you mean products which are on the Organic Materials Review Institute
list of permitted soil amendments, here is a link to their lists.

If you need a truly exhaustive list, I recommend looking at some of the
books available in the Miller Library on this subject. Rodale’s Illustrated Encyclopedia of Gardening and Landscaping Techniques edited by Barbara Ellis (Rodale, 1990) has a very easy-to-use (but probably not exhaustive) guide to soil amendments and fertilizers. Below are are some other titles:

Soils : the right way to use fertilizers, composts, soil conditioners,
soil testing/problem soils 1986

Let nature do the growing : the fertilizer-free vegetable garden / by
Gajin Tokuno c1986

Fertilizers and soil amendments / Roy H. Follett, Larry S. Murphy, Roy
L. Donahue

Fertility without fertilizers : a basic approach to organic gardening /
Lawrence D. Hills

Feeding plants the organic way / Jim Hay

Growing green: animal-free organic techniques / Jenny Hall and Iain
Tollhurst

The following links may be helpful to you:

Colorado State University Extension – Organic Fertilizers

National Sustainable Agriculture Information Service – Sources of Organic
Fertilizers and Amendments

University of California Santa Cruz Agroecology Program – Building Fertile Soil

Washington State University Extension – A Home Gardener’s Guide to Soils and Fertilizers

Oregon State University – Improving Garden Soils with Organic Matter

Utah State University Extension

on intergeneric crosses

I noticed a plant called Echibeckia for sale at a neighborhood grocery—must be some kind of cross between Echinacea and Rudbeckia. Why would plant breeders do this? Are these crosses garden-worthy? Will they be as attractive to pollinators as their parent plants?

xEchibeckia is described as an intergeneric cross (the x represents a cross between two genera), but according to Plant Delights nursery owner Tony Avent (quoted in Greenhouse Grower, March 2015), it does not appear to differ from an ordinary Rudbeckia hirta. “‘We have to be careful with intergeneric crosses and make sure they are truly what they say they are,’ he says. ‘If we don’t, we will lose credibility with consumers, something our industry can’t afford.'”

In her book Butterfly Gardening (Princeton University Press, 2018), Jane Hurwitz mentions this very issue. This trademarked (i.e., propagation prohibited), human-made cross is said to have larger and longer-lasting flowers, faster growth, and disease resistance but it may be “less useful to butterflies and their caterpillars. […] Given the wide number of variables that altered plants introduce, it is easy to summarily dismiss garden plants that have been bred to differ from the straight species as harmful to the garden food web. However, these plants are a fact of life and are promoted by a large, thriving, retail nursery industry […] so the plant buyer should be aware of both their virtues and their shortcomings.”

If you want to grow only those plants specifically known to attract pollinators and beneficial insects, then plant species Echinaceas and Rudbeckias, or choose cultivated varieties with a known track record in attracting them. But if you have fallen in love with this plant, why deny yourself the enjoyment of its presence in the garden? An informal survey of Pacific Northwest gardeners suggests that Echibeckia may do best in containers that are regularly watered and fertilized. Several gardeners found them to be short-lived (more like annuals than perennials), and susceptible to mildew at the end of a long season of blooming. Your experience may differ. Experimentation leads to discovery: it may do well for you, but if Echibeckia fails to thrive or attract as many pollinators as you might wish, there are always other plants to grow.

removing sod and preparing soil for vegetable gardening

We plan to put in a vegetable garden next spring where we now have grass. It is a great sunny spot that we think would work well for this. The question is, after we cut out the sod this fall, someone has suggested we plant rye grass for the winter, is this a good solution? If not, what do we do to the soil this winter? (We plan to bring in some top soil after we take out the sod).

There are several approaches that you can use to get your new garden ready. One is from Growing Vegetables West of the Cascades by Steve Solomon. He
recommends removing the grass, covering it with no more than 1/2 inch of
completely rotted compost or 1 inch of raw ruminant manure, and spread
agricultural lime at 50 pounds per 1,000 square foot. Do this in early
October. Then scatter small-seeded fava bean seed at 6 to 8 pounds per
1,000 square feet. Rototill no more than 2 inches deep and relax until May.
In late May you rototill deeply and or spade in the overwintered garden
area. Then you can plant.

Another information source, Seattle Tilth’s Maritime Northwest Garden Guide,
recommends using an annual winter cover crop to improve the soil. It
suggests using 85% legume and 15% grain for maximum nitrogen fixation. For
the legume, you can use Field peas, Crimson clover, Fava beans or vetch. For
the grain you can use cereal rye, winter wheat, spelt or barley. Most of
these are applied at about 2 pounds per 1,000 square feet. Again you would
rototill or turn under the cover crop in late April or May.

Solomon’s method will provide a better total approach. You also should
consider having your soil tested to find out what is missing and what your
pH level is.

on pruning heaths and heathers

How do I care now, in the fall, for very well established, huge (in some cases) Callunas? Do they get sheared? If so, how many times a year, and how far back? Also, how do I prune my heaths?

The American Horticultural Society Pruning and Training Manual, ed. by C. Brickell, 1996, p. 183, 193 recommends pruning Calluna (heather) in the same way as Erica cinerea. Prune or trim lightly in early spring, cutting stems back where possible to strong shoots below the spent flower cluster.

Local pruning expert Cass Turnbull of Plant Amnesty says the following about heaths and heathers (Erica and Calluna) in her Guide to Pruning (Sasquatch Books, 2006):
“Spring bloomers are sheared shortly after blooming (in the spring). Summer/fall bloomers are also sheared in the early spring (just as new growth starts), so that the attractive seed heads are left in view all winter. An annual light shearing is all that is needed. Don’t wait. Do it now before the plants get too old and woody. When cut too far into old brown, barren branches, a plant may not break bud and green back up. If you have inherited a mature yard, it may be necessary to severely prune an old neglected heather. It will either regenerate or die. Probably the latter. An exception is the tree heath, Erica arborea, which (…) responds well to radical renovation.”

For further information, consult the following websites of nurseries specializing in these plants:
Heaths and Heathers Nursery

Dayton Nursery

purple-leafed shrubs

Can you give me some information on Weigela Midnight Wine and dwarf Nandina? Are there any plant lists of purple-leafed shrubs?

Following is a good description of Weigela ‘Midnight Wine.’ The information comes from the Missouri Botanical Garden, so it is tested and accurate.

WEIGELA

‘Elvera’ Midnight Wine is a dwarf version of the popular Weigela ‘Wine and Roses’ (W760). It is a dense, rounded, low-growing deciduous shrub that typically grows to only 1.5-2 feet tall and as wide. Features profuse reddish-pink flowers and burgundy-purple foliage. Reddish-pink, funnel-shaped flowers (to 1.25 inches long) appear singly or in clusters along the branches of the previous year’s growth in mid- to late spring, with sparse and scattered repeat bloom often occurring on new growth as the summer progresses. Elliptic to obovate, glossy, burgundy-purple leaves (to 3 inches long) turn very dark purple in autumn. Hummingbirds are attracted to the flowers. Original cultivar name is ‘Elvera’, but plants are being marketed under the registered trademark name of Midnight Wine. U. S. Plant Patent #12,217 issued November 20, 2001.

NANDINA

There are several varieties of dwarf Nandina, such as ‘Harbour Dwarf,’ ‘Firepower,’ ‘Nana,’ and ‘Nana purpurea.’ University of Florida Extension has a feature on dwarf Nandina on their website (now archived). There are also plants available from nurseries such as Forestfarm Nursery in Oregon, and Whitney Gardens in Washington.

PLANT SUGGESTIONS

As far as lists of plants with purple foliage, you should find a wealth of information in the book Black Magic and Purple Passion, by Karen Platt, 2004. There are also lists online, such as this page from Iowa State University Extension, entitled “A Passion for Purple.” You can also search Royal Horticultural Society’s Plant Selector and other similar resources by leaf color.

Arbutus winter damage and pruning

I live in Monroe (Zone 7). Two years ago I planted 3 Arbutus ‘Compacta’. I have never pruned them. This year they took the cold winter pretty hard: over half of the leaves are golden/brown/black, with some already falling off. Will the leaves be replaced or do I need to cut the branches and stems to those leaves and hope for the best? The tree/shrubs are in well-drained soil, mulched, facing south/southwest. The leaves hurt the worst were on the upper and north facing side.

It sounds like you are seeing winter damage on your plant. You should probably wait and see if the plant returns to more robust health, and to see if new growth develops where those leaves have dropped before deciding whether to prune it at all. The local web site Great Plant Picks indicates that Arbutus unedo ‘Compacta’ can be cold-sensitive. Arbutus unedo ‘Compacta’ tolerates a wide variety of soil conditions. It grows best in part or full sun and is drought tolerant once established. There are few insect and disease problems, though it can occasionally get aphids and there may be fungal spotting on older leaves if grown in very poor soil. Foliage and flowers may be damaged in extremely cold winters. If you think that there is something else going on besides winter injury, I would recommend taking a sample to a Master Gardener Clinic for diagnosis.

Below is information on winter injury from Washington State Extension and the Pacific Northwest Plant Disease Management Handbook.

propagating roses from cuttings

I am trying to grow roses from cuttings. They are sprouting little leaves but are still under empty soda containers for humidity. When I took a few out of the containers, they promptly shriveled up and died. Should I leave them for another month? I don’t want to tug to see if they have roots, as that will disturb them. Do I apply foliar fertilizer?

I have listed a few useful webpages about propagating roses from cuttings below.

To answer your question about leaving them under cover, I think you probably should leave them for at least a brief while, given the very cold weather. I don’t think you need to apply foliar fertilizer at this stage. The resources below should offer some additional advice on caring for your cuttings.

John Fisher’s book, The Companion to Roses (Salem House Publishers, 1986), says that roses grown from cuttings may take longer to flower than those budded on rootstock, but (if they survive the process) they may live longer and will not sucker. Some roses are easier to propagate from cuttings, such as ramblers and Rosa rugosa, as well as some climbing roses and large-flowered roses.

According to Fisher, cuttings can be taken as early as August. You should choose young shoots with ripened wood that have borne flowers, and lateral shoots rather than leaders. He recommends selecting those shoots growing low on the shady side of the plant, and those with leaf joints that are close together. Make a clean cut just below a leaf joint. The cutting should be about 9 inches long with 2 leaf joints in the top 3 inches. Cut off the tip that has borne the flower and the leaf immediately underneath it. Remove leaves (but not buds) on the lower 2/3 of the cutting, since this is the part that will be planted in the ground. The soil should be a mix of loam and sand mixed down to a depth of about 9 inches, in a pot or V-shaped trench. Before planting the cutting, poke a hole in the soil for it to go into. Moisten the bottom end of the cutting with a cotton ball, and dip it in rooting hormone (or willow water). Put the cutting in the soil and press the soil around it firmly. If you need to protect it from frost, cover it with leaves or sacking during the winter. By summer, it should have formed a root, and should be ready to plant in the fall.

The information below may differ somewhat from these directions, but you may get a general sense of how your methods compare, and whether you want to try any of the methods suggested.

University of California Cooperative Extension

Morrison Gardens

The Southern Garden

removing noxious weeds

I have a non-native bamboo. It’s in a marshy area. It is soft light green. It dries to wood every year. And I cut it like firewood and chip it. Then suddenly it grew back and is growing to an acre size. It even flowers: soft light white vanilla flowers for the bees. Can I rototill it under and seed in native Northwest groundcovers?

It is difficult to do plant identification by description alone, but it sounds like you may have Japanese Knotweed (Polygonum cuspidatum)
It is extremely (!) hard to control this plant. Rototilling it will make hundreds of new plants because it grows from the tiniest root fragment, so do not do that!
There is a lot of good information on it on the Internet, but here are two good links:

King County, which lists it as a Class B noxious weed (control recommended but not required by law)

Washington State Noxious Weed Control Boards