Planting daylilies in containers

We have the ‘Stella d’Oro’ daylilies, the Hyper Yellow variety. They are 9 years old now, going on 10. We divided them last year, and only had a couple of lilies. Where they are planted I don’t believe they have enough sun. When we divided them, instead of 2 plants, we now have 7. I have a huge planter, on a wheelbase, and was thinking of putting 3 of them in it, perhaps 4. They would be located on the sunny part of our deck, which I know would be much better for them. What can you tell me about daylilies planted in containers? The pot is so big, you could grow a tree in it!

Planting your daylilies in a large container should be fine. Here is some general information from University of Minnesota Extension on growing daylilies, in which they suggest growing repeat-blooming daylilies in your containers. In general, smaller cultivars would be good choices for containers.

If you keep them in the pot over the winter, you may want to protect them by covering with a thick mulch.

You may wish to consult the frequently asked questions page on the American Hemerocallis Society website, which includes cultural information, such as the best place to plant daylilies, excerpted here:

“You need to consider four things in determining where to plant your daylilies:

Sun or Shade

Most daylilies do best in full sun. They will tolerate part-shade conditions, but require a minimum of six hours of direct sun per day.
Light yellow cultivars, many shades of pink, and delicate pastels need full sun to bring out their lovely colorings.
Many red and purple cultivars benefit from partial shade in the hottest part of the day because dark colors absorb heat and do not withstand the sun as well as lighter colors.

Type of Soil

Any good garden soil is appropriate for growing daylilies. Daylilies will grow, however, in sandy soil or in heavy clay.
If you have heavy clay soil, add compost, humus, peat moss, and sand to make it more friable.
If you have sandy soil, add compost, humus, and peat moss to lesson its porosity and to increase water retention.

Drainage

For maximum performance, daylilies should be planted in well-drained soil. One method of achieving adequate drainage in problem areas is to prepare raised beds, 3 to 6 inches above ground level.”

Japanese Hollies and root problems

I purchased a gallon size Japanese Holly (Ilex crenata ‘Sky
Sentry’) 5 years ago and put it in a 12″ diameter container. It has
not grown much, and has been looking bad lately, so I thought it
was probably root bound. To my surprise, when I took it out, there
were no new roots–the root ball was about 3″ deep and 6″
across. Is this a normal root for the Ilex? What does it need to thrive?

Since you mention that the plant is not looking healthy, I wonder if it
may have root rot.

According to North Carolina Cooperative Extension, Ilex crenata is
highly susceptible to this fungal problem.

It is possible that there are nematodes feeding on the roots and
diminishing the plant’s ability to get water and nutrients from the soil.

The Organic Gardener’s Handbook of Natural Insect & Disease Control by
Barbara Ellis (Rodale, 1996) says that holly roots grow close to the
surface, so perhaps the size of the root ball is not abnormal.

Missouri Botanical Garden has general information on this plant.

To determine what exactly is causing the plant’s ill health, you may want
to bring pictures and samples of the affected parts of the holly to a
Master Gardener Clinic.

Peach leaf curl and plum pockets

For three years, my plum tree has had leaves that curl and shrivel somewhat. I have heard of aphids causing leaf
curl in plums, but I don’t see many aphids.

I also have a peach tree that has “Peach Leaf Curl” or Taphrina
deformans and the symptoms on the plum leaves look similar to that.
Here is what I wonder:

The peach and plum are at least 100 yards apart. Is it really possible that the peach infected the plum?

With the peach tree the fruits are also affected but with the plum
fruits do not appear to be affected.

Are peach and plum affected by the same diseases?

Both peach and plum trees are in the genus Prunus. Your plum tree’s problem sounds like plum pockets and peach leaf curl, which are caused
by fungus (usually Taphrina).

From Iowa State University Plant Pathology:

Have you noticed lately that your peach leaves appear curled or puckered?
Do leaves appear to be lighter than normal, flushed with red, blistered,
distorted, and curled? Chances are your tree has peach leaf curl, a
fungal disease caused by Taphrina deformans. Although peach leaf curl is
primarily a disease of peach, nectarines are also affected. Peach leaf
curl is first noticed in spring when young leaves start to emerge. The
entire leaf or a portion of it may appear crinkled and curled with
flushes of red or purple . Later on in the season, the fungus begins to
produce spores and leaves appear silvery or powdery gray. Infected leaves
turn yellow and brown and fall off the tree and are replaced by a new set
of foliage. Flowers, young fruits and stems may also be infected.
Affected fruits are distorted with wrinkled, discolored areas on the
surface. Extensive defoliation may affect fruit yield the following year
and may also predispose the tree to winter injury and other diseases.

Plum pocket is a disease in plums caused by Taphrina communis. Leaf
symptoms are similar with peach leaf curl and the plums appear to be
distorted, wrinkled, and puffy. This disease is not considered a serious
problem in most commercially cultivated plum varieties.

Here is Oregon State University’s online guide to plant diseases (aimed at professional gardeners) This is Washington State University’s site intended for home gardeners.

I don’t know if your plum could have gotten the same species of Taphrina fungus
that is affecting your peach (i.e., Taphrina deformans), but the conditions in our climate are probably ideal for this type of fungal disease.
University of California, Davis says that the pathogen which causes peach
leaf curl survives on tree surfaces and buds, and is enhanced by wet
spring weather.

From University of Nebraska Plant Pathology:

Plum Pockets is very similar to the well-known disease peach leaf curl.
It reached epidemic proportions on plum in the 1880’s and sand cherry in
the 1940’s. The disease is still common today but rarely has an economic
impact on stone fruit production. However, its unique symptoms always
seem to peak the interest of individuals who are seeing it for the first
time. The disease is caused by two species of Taphrina. Taphrina communis
(Sadelbeck) Giesenh. has a worldwide distribution. Its hosts include plum
(Prunus angustifolia) and several wild Prunus spp. found in America.
Taphrina pruni primarily infects European plums and is rarely found in
America. The disease cycle of Taphrina communis is similar to that of
Taphrina deformans (peach leaf curl). The fungus overwinters as conidia
on twigs and bud scales. Infection generally begins at bud break when
these spores are rain splashed to susceptible green tissue. Leaves,
shoots, and fruit are all susceptible but symptom development is most
common on fruit. The fungus invades host tissue directly through
epidermal cells. Once the fungus is established, a specialized mat of
fungal cells (hymeneal layer) containing asci and ascospores forms. The
asci are not protected by a specialized ascocarp. Ascospores are
released, germinate and begin budding, much as a yeast does. Conidia (bud
conidia) serve as secondary inoculum in the spread of the disease.
Initiation of the disease cycle is favored by cool wet weather.

You might consider bringing in samples of the affected leaves to a Master
Gardener Clinic for a definitive diagnosis. They may also have more information on whether the disease can pass from peach to plum, or whether your two types of trees simply have two different strains of the pathogen.

Growing culture for cardboard palms

I am interested in finding out if someone there can tell me the
proper culture for Zamia furfuracea. I just acquired one that had
been potted up as a bonsai and put on sale at a local grocery store. I think
they may not have known or cared what it was. This is a plant I
grew outdoors when I lived in California. I’m wondering what to do
with it in Vancouver, WA. The options are greenhouse, patio pot,
indoors, outdoors.

I found general cultural information from Florida State University
Cooperative Extension. This is a zone 9b-11 plant, and your area is probably about zone 8, so I think you would want to grow this with some protection.

University of British Columbia Botanical Garden’s discussion forum describes this as an indoor plant. This article in the journal of University of Arizona Cooperative Extension is about a similar plant, Zamioculcas zamiifolia, often confused with Zamia
furfuracea.

Richard Langer’s book, Grow It Indoors (Stackpole Books, 1995) says to
grow this “handy table-sized cycad” in temperate partial sun with humusy
soil that is kept constantly moist.

Another thing to keep in mind if you are growing this plant around pets
or small children is its toxicity. The ASPCA lists Zamia species (cardboard palm) as toxic. Colorado State University Veterinary Teaching Hospital lists Zamia as toxic to dogs and people.

Pests and diseases of raspberries

It appears that my raspberries may have a disease. I noticed some fruiting canes getting
discolored, then curling leaves, then dying completely. I ripped out ones that were dying or dead, but others seem to be showing beginning symptoms.

There are many potential culprits that could be causing the problems you
are observing with your raspberries. It could be a pest, or it could be a
fungal disease. Remember that summer bearing raspberry canes die after bearing fruit. The canes start to look bedraggled even as fruit is ripening. Once all fruit has been picked these canes should be cut to the ground. Next year’s fruiting canes will look healthy and should not be cut down to the ground.

Have you looked inside any of the affected canes after cutting them? If
you have cane borers, you may find that white grubs have burrowed toward
the base of the cane. Crown borers also cause wilting of new growth in
the spring followed by dieback of the cane. Here are links to
information and images so you can compare what you are seeing with your
plants:

Insects and Diseases of Raspberries from University of Illinois Extension.

Pests and Disorders of Blackberries and Raspberries from University of California.

Washington State University’s Hortsense page on Raspberries (see sidebar on left for diseases and insects)

Raspberry root rot information is available in the Pacific Northwest Disease Management Handbook.

Washington State University Extension’s information for home gardeners says:

“Foliage symptoms of root rots. Root rot is usually noticed when leaves
begin to wilt, turn yellow or brown, and die. Symptoms commonly occur
during warm spring or summer weather and may develop in a few days or
take longer. If longer, leaves are generally yellowish and stunted before
they die.

“Root symptoms of general root rot. Root systems are small, dark brown or
black, and rotted. Since healthy roots may or may not have dark surfaces,
determine root condition by cutting or scraping them. All of the inside
of a healthy root is whitish, but the inside of a rotted root is partly
or entirely brownish or blackish. Wash the cutting tool in soapy water
and swab in rubbing alcohol after cutting.”

You may want to bring samples plus photos of the whole plant to a Master Gardener clinic for diagnosis. There is a link to the current clinic schedule on their website.

Once you have identified the source, you can try to address the problems
and resume growing happy raspberry plants. Oregon State University has a guide to growing raspberries which may be helpful.

Pruning camellias

I bought 2 small camellias a year ago. Their height and width at maturity will be about 10′ x 8′. One has 3 trunks. Now they are 4′ tall and the stems are so close, they are rubbing together and the branches cross-mingled. The trunks have hardened and are about 1/2″ to 3/4″ in diameter. Should I prune crossing branches and stems? Should I limit them to one or two trunks? If so, when and how should I prune? My goal is to have them limbed up or narrower at the bottom with a low tree canopy beginning at about 4′. They just finished blooming. The variety is Kremer’s.

Pruning the camellias when they are done flowering, but before they form new buds, should be fine. You are right to observe that crossing branches and branches which are very close will pose a problem as the camellias grow. In Cass Turnbull’s Guide to Pruning (Sasquatch Books, 2006), the author recommends selective pruning to thin out a camellia. Start by removing any dead wood, and then look for crossing and rubbing branches, taking out some (but not necessarily all–you don’t want to strip the plant) of the most obvious problem branches. Since you have young plants, you should not have too much thinning to do. Turnbull’s book also gives instructions for arborizing your camellia by removing the lower limbs. She recommends that you observe the branching structure before proceeding, and visualize what the plant will look like if you remove
some of the branches.

You may find this pruning guide(now archived) helpful. See second page, section III on “Tree-likes.”

The American Horticultural Society Pruning and Training book edited by Christopher Brickell (DK Publishing, 1996) suggests pruning a young camellia by shortening overlong lateral branches to an upward growing sideshoot. Selecting a central leader (main trunk) is also recommended.

When trees fail to flower

Chionanthus virginicus–at what time can this tree be expected to bloom? And how does it do in the Pacific Northwest? Does this tree needs to reach a certain age or maturity before it blooms–similar to Cornus kousa or some magnolias? Or could it be a cultural problem that keeps it from blooming? Mine is in full sun, moist/fertile soil. It’s been there 3 years and is probably 6 feet tall and over 5 years old (purchased balled and burlapped). Could it be getting too much nitrogen, as it is on the edge of the lawn?

According to local author Arthur Lee Jacobson’s book, North American Landscape Trees (Ten Speed Press, 1996), Chionanthus virginicus blooms between May and July, depending on the year and the latitude. Male and female flowers are on separate trees, and male flowers are more showy. Sunset Western Garden Book also says that this tree flowers here in late spring to early summer. Here is what Oregon State University’s web site of Landscape Plants says:

“Deciduous, large shrub or small tree, spreading, open, 12-20 ft (4-6 m) tall with an equal spread, larger in the wild. Leaves simple, opposite, sub-opposite, narrow-elliptic to oblong or obovate-oblong, 7.5-20 cm long, acute to acuminate, margin entire, glossy dark green above, underside paler and pubescent, at least on veins. Dioecious – male and female plants, but some have perfect flowers. White flowers showy, in fleecy, soft clusters in late spring. Fruit about 13 mm long, egg-shaped, dark blue in late summer.
Sun to partial shade. Adaptable but does best in moist, fertile, acid soils. Slow growing. Male trees reportedly have showier flowers.”

There are a number of reasons why your tree has not flowered. According to The Hillier Manual of Trees and Shrubs, flowers are not seen on young trees (no specifics as to age of maturity, unfortunately). University of Maryland Extension indicates other reasons plants fail to flower.

The full sun and moist soil sound like ideal conditions. It is quite possible that nitrogen-heavy fertilizer could contribute to the lack of flowers. You might consider applying compost to your lawn for nutrients instead of whatever you may have been using. Perhaps you could avoid using the fertilizer and give the tree at least another year to adjust and attempt to flower.

Rhododendrons at peak bloom

Would you be so kind as to tell me when rhododendrons are usually at their peak bloom?

The peak season for Rhododendron blooms would probably be May, but there are Rhododendrons which bloom earlier and later than this as well (March through June). For more detail about which species bloom at what time, you may find this link to Oregon State University’s Landscape Plants web site of interest.

From the Washington Park Arboretum’s list of plants at their peak:

March: Camellia, flowering cherry, corylopsis, daphne, forsythia, heather, hellebore, magnolia, rhododendron, witch hazel.

April: Azalea, barberry, camellia, flowering cherry, halesia, maple, madrona, magnolia, rhododendron, serviceberry.

May: Crab apple, dogwood, magnolia, mountain ash, rhododendron, red bud, serviceberry.

June: Rock roses, brooms, Korean dogwood, rhododendron, stewartia, styrax

Propagating vernal witch hazel

Do you have any information on how to propagate vernal witch hazel?

To propagate vernal witch hazel (Hamamelis vernalis), Michael Dirr’s Reference Manual of Woody Plant Propagation (Varsity Press, 1987) says the following:

From seed:
70% germination after 3 months cold stratification,
75% after 3 warm months/3 cold,
81% after 4 warm months/3 cold,
85% after 5 warm/3 cold.
Fall planting improves success.

From cuttings:
Easy to root and keep alive.

Grafting is not used much as a propagation method.

The American Horticultural Society’s book, Plant Propagation (DK Publishing, 1999) says that softwood cuttings do not overwinter well. One should take early nodal stem-tip cuttings as soon as new growth in spring is 2 3/4 – 4 inches long. Provide bottom heat and rooting hormone to speed rooting in 6-8 weeks. Layering can also be done in spring. Grafting can be done in late summer.

The following is from the Royal Horticultural Society:

“To propagate by seed, harvest as soon as the fruits mature in late summer to early autumn and sow in a cold frame promptly before they have a chance to dry out. Fresh seeds may take up to 18 months to germinate. When the seedlings appear, prick them out and pot them up for overwintering in the greenhouse for their first year. They can be planted out late the following spring and will reach flowering size in about six years.
Witch hazel suckers freely and also can be propagated by layering in early spring or autumn. Layering works well, but the process will take a year.
Softwood cuttings can be rooted in the summer. Volunteer seedlings can also be potted up and transplanted.”

Transplanting Hydrangeas

I want to move my Hydrangea to another location. It is about 3 feet high, and doesn’t have enough room. What is the best time of year to transplant this Hydrangea?

The key to moving your Hydrangea successfully is to do it when the plant is dormant. According to the North Dakota State University Extension Service, it should have no leaves on it when you move it. If you missed the chance to do this in the late fall, you could still do it in early spring before it has new growth. It is a good idea to apply compost on and around the new planting site. There is a Hydrangea website that has a more detailed discussion of the Hydrangea’s transplanting needs.