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Gardening Answers Knowledgebase

Plant Answer Line Question

Keywords: Rosa, Planting time, Planting

When should I plant bare root roses?


The Seattle Rose Society suggests planting in March. The roses should be stored in a cool dark place if they cannot be planted right away.

Other recommendations include soaking the roots before planting (8-12 hours), and trimming off damaged or diseased roots. Try to maintain 3-5 canes per plant, and prune back to 3-5 buds per cane.

Dig a hole wide and deep enough to accommodate the roots. Make a cone-shaped mound of soil in the center of the hole to support the plant. Fill the hole 2/3 full of soil and add water to make a slurry--this gets between the roots. Do not tamp the soil. When the water drains, add more soil and repeat the water fill process until you reach the original soil surface (ground level).

Date 2017-01-13
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Plant Answer Line Question

Keywords: Container gardening, Roots, Planting

For how long can purchased plants remain out of the ground?


If the plants are in pots, they can stay out of the ground as long as needed. Keep them watered and they will be fine. But if they are bare root, then you should plant them temporarily (called heeling in) in a trench until you can get them into their proper holes. The most important thing to remember is to keep the roots moist. Keeping the plants out of the sun can help reduce stress as well. If digging a trench is impractical, then cover the roots with damp towels or burlap bags. Of course, planting sooner is better!

Date 2017-05-17
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Plant Answer Line Question

Keywords: Tulipa, Planting

Will my Darwin hybrid tulips come back every year?


In his book Ask Ciscoe (Sasquatch Books, 2007), local garden expert Ciscoe Morris suggests planting Darwin and Empress hybrid tulips 12 inches deep (rather than the often recommended 6 inches) so that the bulbs will be less likely to divide and the squirrels less likely to dig them up.

Ann Lovejoy says much the same thing...plant tulips 10 inches deep, in a sunny spot, and in well-drained soil, and some are likely to return for several years. (See Seasonal Bulbs, 1995, p.16)

Date 2017-04-14
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Plant Answer Line Question

Keywords: Ribes, Planting

I received a gift today, a shrub/plant named Ribes sanguineum 'Inverness White,' and different neighbors have different ideas of where to plant it.

I only have a little shade in my garden. Will it take full sun, or does it need partial shade? How tall and wide will it get?


In my experience, Ribes sanguineum does best in partly sunny (or partly shady) sites, and does not need much water once established. The plant you have is Ribes sanguineum var. glutinosum 'Inverness White.' This cultivated variety is described by California Flora Nursery as 6 feet tall and wide, but plant size will vary with garden conditions.

University of California Berkeley Botanical Garden's spring 1999 newsletter features flowering currant selections, including the one you have:
"Ribes sanguineum var. glutinosum 'Inverness White' is a proven fast grower with wonderful white flower clusters. As the flowers fade they develop a rosy cast, giving a bicolored effect. The typical form of this variety has pale pink flowers. Roger Raiche found this one on Inverness Ridge in Marin County, and it has since made its way around the state to various gardens, both public and private. This plant was featured, with other new introductions, at a national meeting of the American Association of Botanical Gardens and Arboreta [...]"

Date 2016-12-01
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Plant Answer Line Question

Keywords: Tulipa, Planting, Narcissus, Bulbs

Bulbs in pots - when to plant?

Daffodils & tulips wilting in pots now, what to do with them? Can you put them in the ground right now, or should you wait till fall? Keep them dry, wet, what?


Yes, you can put them in the ground right now or you can lift them, keep them dry and plant them in the fall. Growing in pots is stressful to bulbs, so you may find fewer flowers next year.

Most tulips do not flower reliably each year, even if they were grown in the ground, so many people treat them as annuals (dig up and toss!) BUT some tulips do re-flower (Darwin Hybrids, Fosterianas and species tulips) so if you are not sure what you have, go ahead and replant. Both tulips and daffodils dislike summer water, so make sure you either plant them in a place where they will stay dry or make sure they are planted in really well-drained soil. Mixing gravel into the soil can help with drainage.

Date 2016-12-17
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Plant Answer Line Question

Keywords: Vaccinium, Planting

I planted some two- to three-year-old blueberry bushes about a year ago. I may not have transplanted them correctly. I did not loosen up the root system of each bush, did not shake out the soil mixture into which they were potted, and did not spread out the roots laterally within a two- to four-inch depth from the surface. Will my improper planting technique prevent these bushes from producing the gallons of berries that are in my dreams?

On the assumption that I need to pull them up and give them a better start, I have these questions:
Is this a good time of the year to pull them up?

Am I correct in loosening the root ball, shaking out the original potting mixture from the roots, and then spreading out the roots to a shallow depth?

Do you have any other tips for transplanting blueberries?


I wonder if the bushes have been healthy despite your not planting them exactly according to directions. You could wait and see how they perform this year, and then decide if you need to replant them. If you want to replant them in any case, the best time is in the early spring, after the soil has thawed but before bud break (in our climate, you may want to do this in very late winter).

According to The Berry Grower's Companion by Barbara Bowling (Timber Press, 2000), you should remove half of the canes of a mature blueberry bush at the base of the plant. Prune any remaining canes back to 3-4 feet high. Dig around the root ball, taking as big a root ball as possible. (If they look rootbound, then do gently loosen the dirt around the roots). Be sure to have your new planting hole prepared beforehand [...] the width of the hole should be sufficient to spread out the roots, and it should be deep enough to plant them at the same level they grew in originally. Make a bit of a mound in the middle of the hole and array the plant's roots over it, and fill in the hole. Tamp down the dirt gently, and water well. Once replanted, you can mulch around the plants with organic matter, such as grass clippings or straw.

Here is an article from Oregon State University entitled Growing Blueberries in the Home Garden which may be helpful.

Date 2016-12-30
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Plant Answer Line Question

Keywords: Planting, Hydrangea

I would like to plant hydrangeas along a south-facing shed. The site gets some morning sun and quite a lot of afternoon sun from over the roof of the house. This area currently has moss growing on it and has not been previously used for planting. Your reply will help me to decide whether to plant there or not.

I have amended the area where I have planted the hydrangeas with chicken manure and compost. I dug holes about 14 inches deep and and about 14 inches square. I also put a spade full of gravel at the bottom of the hole to improve drainage as I suspect that the base soil is mostly clayey.


Most hydrangeas will do well in sun to part shade although full sun in a hot climate would be too much. You also want to bear in mind that hydrangeas, especially Hydrangea macrophylla, prefer adequate moisture. According to Michael Dirr's Hydrangeas for American Gardens (Timber Press, 2004), an inch of water once or twice a week should be sufficient as long as the plant's soil needs are met (consistently moist, well-drained, acidic soil which is rich in organic matter such as leaves, compost, well-aged manure). Some species of Hydrangea tolerate heat better than others, according to Dirr. Hydrangea macrophylla, H. serrata, and H. umbellata do not fare as well as H. paniculata. Some species, like H. quercifolia and H. aspera, prefer shadier spots. Dirr recommends using drip irrigation for plantings of Hydrangea, specifically using drip tubing, extender lines, and emitters attached to a garden hose, possibly with a timer.

The Michael Dirr book says that good soil preparation (not just of the planting hole) ahead of time is the best thing for hydrangeas. He does not subscribe to the rule sometimes put forth, that the hole must be 3 times as wide as the root ball. I also consulted Hydrangeas: A Gardener's Guide by Toni Lawson-Hall and Brian Rothera (Timber Press, 1995) which says the hole should be 2 times the rootball's width and depth. Be sure to check the state of your plants' roots. You want to make sure they are not coiled in a spiral or restricted in any way. You may need to tease out or prune the roots a bit before planting.
Professor Linda Chalker-Scott discusses planting procedures in her book, The Informed Gardener (University of Washington Press, 2008), advising that the planting hole only needs to be the depth of the root system, but twice the width. She also recommends against amending the planting hole in any way. Backfill the hole with native soil, not a soil amendment. The idea is not to 'spoil' the plant by putting rich compost just in the hole, which will deter the roots from spreading out into the surrounding area. Here is more of her writing on this subject.

You have already amended the surrounding soil, so the addition of gravel to the hole is not necessary, and is possibly not a good idea, according to general planting information from University of Minnesota Extension. Here is an excerpt: "If soil drainage is inadequate, species that are tolerant of poorly drained soils may be planted, or soil drainage may be improved. This can be done in two ways. If a hard pan is present (a compacted, impermeable layer of soil) with an underlying layer of well-drained soil, a hole can be dug down to the permeable layer to provide drainage for the planting hole. If the soil is poorly drained and there is no well-drained layer below, a tile system can be laid. This, however, is expensive and requires the assistance of a professional for proper design. Simply adding gravel to the bottom of the planting hole will further decrease oxygen availability to the root system."

Date 2016-11-17
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Plant Answer Line Question

Keywords: Vegetative propagation, Heuchera, Planting

Why does my Heuchera lift out of the ground while growing? Should I replant it back down into the soil? If so, when and how do I do this?


I have observed this in my own garden and wondered why those heucheras keep heaving themselves out of the soil. According to Heucheras and Heucherellas by Dan Heims and Grahame Ware (Timber Press, 2005), most heucheras "require resetting or mounding every two years. A heuchera is in need of such a treatment when its rhizomes' stems exceed three inches in length. [...] Remove stem tips with a sharp knife or razor and plunge them into the ground or into potting soil to make more plants; lateral buds will emerge the following spring. Resetting a plant involves 'popping' the rootball out of the ground, digging a deeper hole in the same spot or elsewhere, and resetting the plant with 3 inches of soil mulch. It is important not to cover the crown tips, as this may cause rot or death. Some people think it is easier simply to mound 3 inches of mulch over the plant, but we prefer resetting--which is also a good opportunity for dividing the plant.[...] Early spring, when the ground thaws, is our preferred time for this operation. Without this treatment, many heucheras show less vigor, less flowers, and less foliage."

Date 2017-05-12
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Garden Tip

Keywords: Vegetable gardening, Planting, Almanacs

To find out which days in the lunar month are most favorable for planting root crops turn to the Old Farmer's Almanac online at www.almanac.com The website is a condensed version of the printed edition with all the weather information a gardener could ever want, plus folksy gardening tips, frost dates and a manure guide. Check out the Growing Vegetables Chart to determine when to start seeds indoors or in the ground, when to fertilize and when to water through the growing season.

Date: 2007-04-03
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April 11 2017 13:50:16