Horticulture Guy

Q. How do i keep crows out of my cherry trees? I heard an owl decoy might work ..Help? Scott Landon - Surrey, B.C.

A. I am sorry to say that the “Natural Enemy Scarecrow” sold to control “birds” is also the owl decoy (like the great horned owl decoys) used to attract crows for hunters – thus the term decoy. Where the great horned owl decoys may frighten smaller songbirds they instead incite mobbing behavior. Hunters use this to their advantage by setting up an own decoy and maybe a few fake crows on the ground nearby and then make an audible crow distress call. Crows are arguably the most intelligent birds rivaling and some claiming exceeding the intelligence of parrots. So if the crows are coming by to feed on your cherries (which they will remember to come back this year) they will find a predator and likely proceed to mob it. Especially if it is near their nesting sites. Once they take out your scarecrow they will be free to feast. Reflective scare tape may provide short-term control but crows may habituate to that as well if used for too long a period of time. There is also motion-sensing water propelling scarecrow sprinkler that can be set up to protect the trees. But the most effective method would be to exclude them from the tree using bird netting. There are large sizes (28’x28’) made specifically for protecting fruit trees. Put them up at least a week before you think they will ripen since the crows (just like the raccoons) are willing to eat fruit a little on the sour side and could still beat you to your fruit.

-- HG

Q. I just recently mowed for the 1st time this year.  The moss is so thick that it’s difficult to mow.  It has not been thatched in years but we have used weed and feed with moss killer in the feed.  This year is the worst ever.  Will using dolomite lime help at this point?  Or is it too early? Cricket Schackel - Graham, WA

A.  So you haven’t thatched in years and you have been using weed and feed with moss killer.  As Dr. Phil would say “How’s that workin’ for you?”  Adding lime will influence the pH of the soil, which could influence the health of the lawn, if that is the problem here.  The ideal pH of a lawn is between 6.5 (slightly acidic) to 7 (neutral) although lawns can grow well with pH down to 6.0.  If you have been following my column you may recall that a few weeks ago I mentioned that this is also a good range to keep the soil because the soil microorganisms that break down thatch work best in this range.  I also mentioned that excessive fertilization also promotes thatch.  Moss in the lawn is a symptom and therefore solely treating the symptom is not a sustainable course of action.  Moss overtaking a lawn is symptomatic of conditions that are not ideal for lawn growth (and therefore favor the moss).   When the moss treatment is combined with the lawn’s fertilizer there is a good chance you will either over fertilizer to treat the moss.  Hopefully you can see the vicious cycle that can occur.  So first you need to test the soil’s pH and fertility and apply fertilizer and lime as needed.  Then check to see how thick your thatch layer is by digging up a small section that can be replanted.  More than ¾ inch layer means that you need to take corrective action.  You should also check to see how the drainage and light levels are for the lawn.  If the light levels are too low or water pools then you favor moss over grass.  Correct these problems if necessary and then treat the moss separately and then you are on the way to a sustainable lawn.

-- HG

Q.  We have a long low laurel hedge that is set about 10 feet too far into the property and we’d very much like to move it further out. I know laurels are pretty forgiving of pruning, but can they survive being moved?   At what time of the year would be best, and how would we best go about it? How much of the root structure is needed? Does one prune it right after? Does it need fertilizer etc.  Thanks so much! Virginia Keyton - West Vancouver, BC

A.  This all depends on how long the hedges have been in place and how big they have become.  When I moved into my house I had a 30-foot tall 15-foot wide hedge along a property line leading up to the side of the house that made the house look Lilliputian.  My goal was to remove them so I cut them down with a chain saw and tried to remove them with a maul.  I quickly found out just how hard their wood is.  I wore down a few blades and had to enlist the help of a backhoe to remove them.  A friend wanted to try and salvage the large root systems I wrenched from the ground and planted them on their property without success.  This of course is an extreme case and my intentions were removal and not saving the shrubs.  I think if they are not that large you will be able to move them without incindent.  Since they are evergreen I would suggest moving them in the fall just before the rainy season kicks in.  I know this doesn’t help for this fall but root-pruning a year in advance would also help their transition.  The more root system you can maintain during the transplanting process the better the chances are for the tree’s survival.  At some point you will have to determine if it is worth the work since you could plant a new hedge and they would grow in quite quickly. 

-- HG

Q. Dear Peter, I have had a Ginseng Ficus Bonsai for almost four years. Its size has increased by about a third. I have only watered it and it was doing fine until recently. Now it is beginning to drop leaves. Do I need to re-pot it into something bigger? If so, is there a certain way to do it? Please help, this is the only plant I’ve ever been able to keep alive more than a couple of months.  Thank you, Georgia Riddle - Tacoma, WA

A.  Ficus trees are a very useful genus for bonsai plants.  Most are forgiving of severe pruning and adapt to the rigors of bonsai culture.  The species you have as a bonsai is Ficus retusus.  This species is very popular for “starter” bonsai because they are one of the best Ficus for bonsai culture.  This tree can grow 50-60 feet tall in its native environment.  Even the common Ficus benjamina, a regular in homes, office buildings and shopping malls, is used to make bonsai.  Consider first if anything has changed in the environment of this bonsai.  Reduced light levels can trigger leaf loss.  Ficus are sensitive to change in light intensity.  The plants adjust by dropping the old leaves and growing new leaves adapted to the new light levels.  Changes in humidity (read decreased humidity) as well as cool temperatures (below 55 degrees F) can also trigger leaf loss.  Bonsai are on such a “short leash” when it comes to water so it wouldn’t take much to trigger leaf loss.  If you said you have “just watered it” does this include a liquid fertilizer? If not four years is a long time for a bonsai specimen to go without any supplemental nutrition.  I would also guess that it is due for repotting since the recommendation is every 2-3 years.  If you are not sure how to do this you can find some very good books on bonsai or you can visit the nearest bonsai society chapter: Olympia Bonsai Society. Meets at 7:00 PM on the second Thursday of each month at the American Legion Post #3, 3201 Boston Harbor Rd. NE, Olympia, WA.  Rep: Gene Tsuji (360)491-0593.  Also the Pacific Rim Bonsai Collection in Federal way also has regular lectures throughout the year (www.weyerhaeuser.com/bonsai/).

-- HG

Q.  Dear Peter:  I am searching for the “perfect tree” for my backyard.  We have a fairly standard city size lot and I am looking for something that is no more than 20-25′, disease resistant and doesn’t require much pruning i.e. no suckering/water sprouts (I have MS and can no longer do the ladder work).  It would be wonderful if it had a spring show of flowers and a nice fall/winter foilage color, berries and/or attractive bark.  There is plenty of sun available and watering is no problem. This would basically be a specimen tree so the more spectacular the better.  Thank you - Maria Johnson - Tacoma, WA

A.  That’s a tall order so I don’t know if I can give you the perfect tree but I can try and satisfy some of your requirements. I am sure there may be others but my offering to you is the Persian Parrotia (Parrotia persica).  It is a moderate grower reaching anywhere from 15 to 35 feet depending on the growing conditions.  It is upright when it is young and rounding to an oval shape as it matures.  The Parrotia is a very nice pest resistant deciduous tree, which has something to offer in each season.  It has half inch maroon flowers that form in clusters in the late winter/early spring before the leaves emerge.  The leaves emerge purple tinged and turn to a rich green as the season progresses.   The interesting gray bark peels as it ages to reveal various colors from silver and white to cinnamon red.  The tree is probably best known for its wonderful fall color even in our Northwest region.  The leaves slowly evolve from yellows and progress through orange toward crimson as the fall unfolds.  Although there are more brilliant fruits out there it does produce a tan colored fruit.  Its normal habit is to be a multiple stemmed tree but early pruning (sans ladder) can train it into a single stem tree if that is your preference. 

-- HG

Q. How can I get a successful start of Coulteri Romneyii.  I have a healthy 5’ plant, but each root that has been dug up and potted dies.  Thanks for your guidance, Linda Finkas - Lakewood, WA

A.  The Tree or Matilija Poppy (Romneyii coulteri) is a shrubby perennial that has white petals with yellow pom-pom centers.  I bet your plant is so impressive that you want some more.  Don’t feel bad about not having had success yet as these plants can be difficult to propagate.  The easiest way to have success is to cut a section of root that has already sent up a sucker.  These plants can spread by root suckers but in some gardens they are reluctant.  If this is the case then try again with your root cutting.  Be sure to select a section of root that is at least as thick as a pencil.  Each piece should be at about 6 inches long. You can then divide the root into smaller 2 inch pieces.  Place the piece horizontally in a new or sterilized container filled with soilless potting mix.    Often cuttings are placed vertically but in this case they should lay on the soil surface horizontally.  Push them in slightly so they make good contact with the mix and then cover with about a half-inch of sand.  Keep them from freezing and moderately moist.  Hopefully you will see some sprouts in a few months.  If this is not a named cultivar like “White Cloud” you can also collect some seeds.  Soaking the seeds in rubbing alcohol for about 15 minutes helps weaken the seed coat (scarification) and speeds up germination.  This replaces the fire-induced germination that takes place in its native chaparral habitats of California.  Some people burn pine needles above the planted seeds but the rubbing alcohol seems to do the trick as well.  Let me know how you do.  I might like one of them myself.

-- HG

Q. I have a rhododendron. Dark green upon planting. Western exposure. Leaves and new growth turn pale green and droop. Tries to set buds and flower but buds do not mature and flowers are extremely small and die back quickly upon opening. Paul Faro - San Leandro CA

A.  Sounds to me like you have a fungal root rot disease (Phytophthora spp.).  Although pale leaves could be caused by improper pH/nutrient problems, the drooping and die back sound more like this disease, which is encouraged by poorly drained soils and planting deeper than it was in the container.  Root rot disease is tricky to diagnose since the symptoms can be confused with cultural problems like low pH/nutrient problems (pH should be between 5.5 and 5.6 to allow minerals like iron and magnesium to be absorbed) which would result in pale green leaves or drought which would cause drooping and difficulty in absorbing nutrients.  The way you presented the symptoms makes me thing it is more likely root rot disease.  This is not easy to treat with fungicides and you may be faced with replacing the shrub.  Rhododendrons are not the only species vulnerable to this disease so you will need to ask for a resistant variety of Rhododendron or a species of shrub that is not susceptible. You may be able to bring a sample to your local County Extension for accurate diagnosis and also to find out what a suitable replacement shrub may be for your area. 

-- HG

Q.  My flowering cherry tree has small 1/4″ holes around the trunk spaced about 1″ apart.  Have never seen a woodpecker.  Any ideas? Tip Thibodaux  - Spanaway, WA

A.  About 2 months ago I answered a question about sapsuckers.  This sounds like the same thing.  Damage by boring insects is usually not equally spaced around the tree.  In this case the sapsucker (which you just may not have noticed) start a little hole to let the sap ooze out and then come back later to eat the bugs that are attracted to it.  Cherry trees are one of the sapsuckers favorite trees to work on.

-- HG

Q. I have an 8′ tall Pee Gee in a pot; would it be happier in the ground? How and when to prune? Fertilize? My Black Pussy Willow bush has some catkins; how do I get these to be more plentiful next year? Thanks, Beverley Long - Lakewood, WA

A.  All anthropomorphizing aside it depends how big a pot your 8-foot Pee Gee Hydrangea is in and how much care you want to provide it.  Bonsai are grown in minuscule pots.  Does this make the plant happy?  I’ll let you know if and when one of my plants talks back to me.  More importantly is that the smaller the pot, relative to the size of the plant, the more intensive the care and monitoring will be.  Bonsai enthusiasts must plan for care of their specimens when the go on vacation.  Containers must provide for all the elements a good garden site would provide including adequate water and nutrients as well as drainage.  So if you 8-foot Pee Gee Hydrangea is in a one gallon container it is going to be a lot more work than if it is planted in a 25 gallon barrel or in the yard.  Pruning your Pee Gee for dead or diseased wood can take place at any time other pruning can be done late winter to early spring.  In a container I find that it is good to use a slow release fertilizer or a dilute liquid fertilizer with each watering.  This is especially useful when using chemical fertilizers, which are generally salt-based and can interfere with the root system if their levels build up in the container.  As for your black pussy willow be sure that you are not pruning late in the season, as this will remove the catkins.  The new catkins (flowers) form early in the season.  The older and healthier plants will produce more catkins so there is no magic to getting more catkins next year - good old-fashioned care and patience.

-- HG