Horticulture Guy

Q. My wife and I have 20 hanging baskets on our deck.  This year we used trailing petunias.  They started out very nice but as the summer went along, they got really spindly and didn’t produce any blooms to speak of.  We intend to use petunias again next year.  Can you suggest what I can do differently to produce healthy, vigorous plants that trail and bloom?  We see huge baskets hanging around our town with thousands of blooms.  Thank you. Ron Wilhelmson - Gig Harbor, WA

A. Without information on your care regimen or the exposure of your deck I can only make general recommendations as to how you can be more successful next year.  If your deck is in the shade you may want to consider a shade tolerant annuals like begonias, browalia, or impatiens, instead of trailing petunias, which prefer full sun. Petunias will become leggy and not bloom if they do not receive enough direct sun during the day. I would suggest a minimum of six hours direct sun a day.  If the plants are receiving sufficient sunlight then you will need to keep them well watered.  Smaller hanging baskets can require daily watering during our summers.  Some days they may require water twice.  Trailing plants are especially susceptible to drying out because the surface area of the root system and the water holding capacity of the soil is limited by the size of the pot. As the plants grow and trail the leaf surface area continues to increase as the summer progresses.  This means more water is used and transpired from these leaves than the limited soil and root system can support.  Another consideration is the plants nutrition over the course of the summer.  Soilless mixes are the norm in hanging baskets.  This means that there are limited nutrients contained in the container.  The plants depend on you to provide their nutrients.  You can provide a diluted fertilizer in each watering, fertilize every two weeks during the growing season (in both cases with a water soluble fertilizer) or apply a balanced slow release fertilizer at the beginning of the season.  Most slow release fertilizers will provide nutrients for 3 months.  Use a fertilizer made for growing in containers, or for flowering plants.  If you are growing the plants in a soilless mix be sure that the fertilizer provides primary (nitrogen, phosphorus, potassium), secondary (calcium, magnesium and sulfur) and micronutrients (iron, manganese, copper, boron, zinc and molybdenum). 

-- HG

Q. I would like to cover lawn with mulch. I have heard to lay newspaper down and then place the mulch on top. How much newspaper and how much mulch works? I am thinking about using wood chips for mulch. Mark Bruser - Tacoma, WA

A. Yes if your goal is to replace the lawn without having to dig it up then you can use newspaper and mulch to replace the lawn.  First step is to mow the area you want to convert as low to the soil line as possible.  This is called scalping - a term used by turfgrass professionals for what can happen on uneven areas of turf mown by a large deck.  While usually the goal is to prevent scalping your goal is to scalp the whole area.  Then you lay down newspaper in an overlapping pattern.  Make a six to ten sheet thick layer.  If your lawn is weed free you can lean toward the six sheets.  If you have a weedy lawn then lean toward the 10 sheets.  Water down the sheets to set them in place (rain will work as well since you may be doing this in the rain this time of the year).  Then you can mulch them with 2-3 inches of your favorite mulch - in your case wood chips.

-- HG

Q. I have basil growing in a window pot that I grew from seed. It has been healthy all summer until the last several weeks. It has tiny bugs (I guess) all over it, tan in color. They look like tiny grains of tan rice. I put the pot with the basil in the bathtub and gave it a good shower, rubbing as many of the critters off with my fingers as I could. That was about 3 weeks ago and the basil has been bug-free till now. I have the pot back in the shower, but what are these things and how can I prevent it from happening again? I used bagged potting soil for this plant. Having these bugs in my kitchen is starting to get to me. Marianne Comstock - Port Orchard, WA

A. Your description sounds like thrips.  These insects have piercing/rasping mouthparts used to feed on their host plants’ sap.  In commercial greenhouse production thrips can be vectors for viral diseases.  I ran across them once in a commercial greenhouse and my impression was that they are difficult to control in this environment. The adults have wings and are about 1/8 of an inch.  There are many species of thrips some of which are tan as you describe and longer than wide and could be described as a grain of rice as you have.  You had a pretty good infestation if they were that visible.  Your shower method probably removed many of the insects but probably not all. The young larvae are small and can hide in the joints of the plant.  Insecticidal soap or a neem-based soap would be a good solution for your situation.  Weekly inspections and sprays will be necessary until you have controlled them. Neem can influence the larvae development disrupting their molting and ability to mature (and therefore reproduce). Neem in a saponified formula can also control the adults. Insecticidal soap alone doesn’t have any growth regulating capabilities.  Of course contact of the insects skin with the soap is essential to control.  I may also suggest you consider removing the plant and starting again with clean material. In addition, unless you are providing additional lighting basil plants can languish during our winters even in the brightest windows.  If you have any other plants in the house I would monitor them to be sure the thrips haven’t spread to other plants.

-- HG

Q. About 4 years ago I planted 13 filbert trees in my yard.  This year there looked to be a fair amount of nuts when I left for vacation in mid August.    By the time I returned, squirrels had gotten every single nut.  Is there some way of getting some nuts for myself?  Something that scares squirrels away?  How do professional hazelnut growers get any nuts? Philip Peterson - Puyallup, WA

A. I am going to guess that you are having problems with the infamous gray squirrels.  Of the animals that had to be imported from back east why couldn’t they have brought one I really miss like the cardinal. Well they are here now and we must deal with their periodic garden and bird feeder raids. They don’t even seem to want to share when it comes to nuts.  It is not as easy as wrapping the tree in bird netting since the squirrels can chew their way through this plastic (I guess that is why it isn’t called bird & squirrel netting). The Northern Nut Association describes squirrels as “a constant nuisance” in their online FAQ page but they don’t mention how they control them. I don’t personally know any hazelnut/filbert (Corylus) growers so I am not sure when they decide the loss due to squirrel feeding requires control. My suspicion is they would exclude them from getting into the trees using a metal baffle (a cone with the wide opening facing down) on the tree trunk and limbing up the tree (removing lower branches) to avoid the vertical squirrel jump.  Baffles work better on larger trees where the baffle can be at least a foot or two up the trunk. They may also exclude them from orchards using an electrified fence. 

-- HG

Q. Hi Peter, I had some great peppers this year (no brag, just fact)- jalapenos, serranos, poblanos, czech black, and Blushing Beauties. I really hated to till them under this fall. I understand peppers are perennials back in their own parts of the world. Is it possible to pot pepper plants at the end of the season, bring them inside over the winter, and re-plant them the next spring? Would I get bigger, better, more peppers? How long will a pepper plant live taken care of this way? Is it worth the effort? What is reality? Ok, one too many questions. Thanks again, Henry Raynor - Puyallup, WA

A. I am also quite happy with my pepper crops this year.  I tried two short season sweet pepper varieties Northstar (red) and Golden California Wonder (yellow). This year was my all time best number of ripened fruit since I moved from NJ!  I had a stuffed pepper feast.  I still have a few fruit on the plants that I need to bring in and eat.  We had a close call back in October that caused some burning on my zucchini and basil but no hard frosts yet but I’ll probably get out there this weekend and get the rest. Now back to your question. I, for one, won’t be digging them up and over-wintering them.  Although some members of the pepper genus Capsicum are perennial, our garden peppers (both hot and sweet) are very short-lived perennials to the point that they are botanically named C. annuum (the specific epithet means annual if you hadn’t deduced that already).  So even if the plant were able to get over the transplant shock of being potted up and you had ideal indoor growing conditions (which here would mean supplemental heat and light) the plant would be nearing the end of it’s productive life and would most likely be out produced by new plants.  Better to spend the energy on starting your own seedlings as early as the end of January if you are willing to repot them several times.  Grow them under growlights since even a sunny window isn’t so sunny during the winter.  This will allow you to set out larger plants next year.  Larger plants can mean more fruit by the end of the next season.

-- HG

Q. In April, I planted new black raspberries (munger variety). They have grown to 8ft with only 2 vines per hill. Should I cut them back to 5ft (like I did the old red plants) or can I trellis them like loganberries. I’m looking for maximum yield. Gary Pedersen - Tacoma, WA

A. Munger is a popular variety in the PNW both with home growers and commercial growers.  Commercial growers favor them because they are robust and good for mechanical harvest. There are many different ways to prune and train different brambles (blackberries, raspberries, black raspberries and their various crosses).   Much of this has to do with the habit of the particular type you are working with.  Brambles can be upright, semi-upright, or trailing in habit. The most typical pruning scenario for the Black Raspberries (Rubus occidentalis), which has an upright habit, is to pinch the first year canes (primocanes) back at 2 feet tall to force out lateral branching.  This keeps the fruit production in a more compact space.  Then in the winter the laterals that formed are cut back to a foot or so forming an oval shaped hedge.  I believe this method was translated from the commercial growers back to the home growers.  You have missed the window to prune them this way.  Any pruning done during the winter reduces the number of flower buds that will be produced in the second year when the primocanes (first season growth) become floricanes (second year flowering/fruiting).   Once the canes fruit they are mortocanes - no just kidding  - I made that one up.  But you get the idea. The canes die after the second year and should be pruned out.  So if you want to get maximum production this year just give the canes some support and then start a new pruning regime the new primocanes.  The loganberry you mention has a trailing habit and therefore can be trained in a variety of ways on trellises. My favorite way for my Marionberries (trailing habit) is a looping system on wires.  This allows the use of the full length of the canes and maximizes fruit production.

For more info on the various ways of training brambles see the WSU online publication: http://cru.cahe.wsu.edu/CEPublications/eb1640/eb1640.html

-- HG

Q. Dear Peter: I like to grow sweet corn in my backyard, and at harvest time I always find that earwigs have taken up residence in the leafy coverings of the ears. When picking the corn, in addition to live earwigs, I find many dark particles, which I presume, are earwig droppings. Are you aware of any means of keeping the earwigs away? I’m primarily concerned about the sanitary aspects of handling the corn ears. An environmentally friendly solution to my concern is preferred. Thanks for any help you can provide. Paul Jacobson - Puyallup, WA

A. I think your presumption is correct and these are earwig droppings. I can’t really speak to whether the excrement of earwigs poses any health risks to humans but there is the obvious “yuk” factor associated with finding these insects and their droppings in your corn. But if they are not found in the kernel layer you should be able to shuck them outside (I usually shuck mine right over the compost pile to save a step) and they will not contact the kernels. If you want you can clean the corn with a mild detergent (or if you want to be “tres chic” you can use the new vegetable soaps that are on the market) will eliminate any sanitary issues. There are ways to trap earwigs. like placing pieces of bamboo segments on the soil with on open and one closed side or earwig traps After they are caught you then dump them into rubbing alcohol to dispose of them. But the earwigs may still prefer the corn to any traps you set. In this case you might consider restricting access to the corn altogether. Next year you can apply a band of tanglefoot tangle trap (an organic sticky product used to band trees) around the base of each corn stalk. This will keep them from being able to climb up the plants. Apply it when the corn sets tassels. Monitor the band since things may stick to it making a bridge across the sticky moat.

-- HG

Q. I have a row of 16 - three year old “Emerald Green” arborvitaes.  I suspect they have arborvitae leafminer (cypress tip moth).  I have noticed the moths before, but now there are more and I just recently noticed brownish-yellow tips on a couple of the trees.  All of them have lots of needles falling from the interior.  My problem is that I have received conflicting reports about the proper time to spray for them, and is there anything I can do in the meantime to lesson the damage? Thank you! Linda Brieger - Tacoma, WA

A. The way to gain control over any pest population is to know its life cycle.  Spraying is geared toward eliminating the adult form of the insect, which is a moth as the second of the two common names indicates.  The most likely reason you may see conflicting reports on when to spray the moths is because of varying times the moth may emerge in different regions where they are present.  They are generally active in our area from April to June with a peak of activity in May.  The moths lay their eggs during this period and the eggs hatch and then burrow into the needles of the host plant.  According to the WSU extension the adult moths are silver-tan and approximately 1/4″ in length. External sprays won’t have an effect on the larvae once they burrow so you need to spray weekly during this period to catch the larvae as they hatch.  Systemic insecticides are able to kill the larvae once they are in the host.   You can limit systemic insecticide spraying to one application near the beginning of the activity since they generally remain effective for some time (see labels for instructions).   As far as “in the meantime” a sprayless solution is to prune out and destroy infected parts of the host now so that there are less moths in the spring.  You can also keep an eye out in the spring for the white cocoons that form after the larvae exit the host to become adult moths.  You can remove these as well. 

-- HG