The Natural Gardener: Aphids on Roses are Good

          A couple of weeks ago, I saw a bad infestation of aphids on Betty Boop, my favorite rose.  I also saw some soldier beetles already on the job, eating them.  I checked them a few days later, and both aphids and soldier beetles were gone.

But I know that those soldier beetles laid eggs under the leaf mulch in my beds, and their larvae will be patrolling under that mulch for the next 10-11 months, eating any insects they can catch and kill.  They pupate and become adults in April and May and emerge, ravenous for aphids to make their eggs.

I learned this the spring after I bought my house, in 2000.  All the roses that came with the property were heavily infested with aphids, and I waited for weeks for lady beetles to show up and clean them up and make their young, who likewise eat aphids.  But the infestation just got worse, until I got nervous and decided to spray them with soap.  I was heading out there with the spray bottle in hand, when I saw about 50 soldier beetles flying around the most infested bush and mating—so I didn’t spray but I did look up these red and black beetles and learned their habits.  Within a few days, both aphids and soldier beetles were gone.

I had been waiting for lady beetles because, in Arizona, I had a single broccoli plant that was infested with aphids.  I had learned that aphids are specific for particular types of plants.  This being the only brassica in my garden, I knew there was nothing else that they would eat, so I didn’t pull the plant, wanting its seeds.  After a while, it became a lady beetle factory, feeding at least 100 of a several different sizes and colors of lady beetles, including young and pupae.

But here in Southern Oregon, lady beetles have to compete with soldier beetles, which, with their short adult life span, are more ravenous when they emerge from the mulch.
Later in the summer, I tend to have aphids on corn, which attract lady beetles in large numbers and don’t really hurt the corn.  They also do the same thing on sun flowers, though birds are more likely to eat them there.  A couple of years, I had large, grey aphids on my fringe pussy willows, which were eaten by hummingbirds, chickadees and woodpeckers.

Aphids are manna for predators that eat them, crowding together in large numbers for easy picking, full of sugar as well as protein.  Those that grow on poisonous plants, like hellebores, often are not eaten by anything.   I have seen soldier beetles eating aphids on hellebores, but only once, so I am more likely to spray them there.  But most of the time, they are useful to bring in predators that might stick around and eat other insects as well. 

But soldier beetles won’t lay eggs where there isn’t any mulch cover for their young.  Don’t use finely-ground bark, which leaches its natural preservatives into soil and kills everything in the soil but plants.  Coarse bark, like walk-on fir or nugget bark, can provide shelter and help keep soil moist, but the best garden mulch is leaves, which feed fungi and soil life and become rich soil.

         

Rycke Brown, Natural Gardener          541-955-9040        rycke@gardener.com

The Natural Gardener, Gardening in March

          March has come like a white wolf in sheep’s clothing, with snow in the middle of a week of rainy weather on the 5^th and 6th.  Can’t garden until it melts, but unlike the storm in January, it is gone on the 7^th.  February didn’t have its usual two-week break of warm, sunny weather; there was some sun between the rains, but not a lot of warmth.  Daffodils barely started to open, when they are usually in full bloom by mid-month. 

          We are told, in this area, that we should cut back the roses when the forsythia blooms, but as often happens, roses have broken buds and are leafing out well before the forsythia even breaks a bud.  This gardener crowned most of her roses before the end of February, though there remain two customers who haven’t been served yet.  Not to fret; growth is slow and little will be lost in waiting another week or two. 

We cut roses back to the crown, the hard knot of wood at the base, rather than the usual foot tall, because black spot grows all over the stems, and will just re-infect the leaves if any stem is left on the crown.  Nearly every rose in town has black spot due to our mild winters, though Rosa rugosa is pretty resistant.  This is not the only time one can crown a rose.  A rose crowned during the spring growing season will come back to nearly full height and bloom within a couple of months.  Crowned in summer, it will grow back and bloom even faster in the heat. 

March has the equinox, the day and night of equal length, on the 20^th.  One can plant cannabis clones or seed outside after this date, and they will not bloom prematurely as long as one does not deprive them of the increasing day length before 6 weeks after planting.   The way to do that is with a “light depo” or light deprivation house, in which one pulls a cover over the plants to give them only 12 hours of light, which starts them blooming heavily and makes their buds more solid.  These are being advertised on the radio and elsewhere.  

This year, it may pay to wait a little longer to plant, for sunny weather to warm the soil up, as your clones or seedlings will be eaten by bugs if they are planted in soil too cold to get them growing.   The same goes later for regular summer food crops; if bugs eat your plants, replant.

But now is a good time to plant peas, potatoes, onions, lettuce, spinach and other greens, preferably from seed or bulb.  Pansies and petunia plants are in the stores and will be happy in the chilly ground.  Cyclamen and hellebores are blooming and will be available at the Growers Market this month.

Blueberries at Sandy's Nursery.  Southern "Legacy" are on the right, with leaves.

It is time to plant blueberries, which are available now at Sandy’s Nursery in #2 pots.  They have included one variety of Southern, Legacy, with their usual Northern varieties.  Southern blueberries take our hot Southern Oregon summers a bit better than Northern varieties; they keep most of their leaves through the winter and will drop them after they bloom and new leaves grow.  Their branches are thinner and their leaves smaller, and they often turn colors through the winter.

Keep in mind that blueberries want to be planted in very loose, rich soil.  If yours is not loose enough to dig with your gloved hands, put the plant on top of the ground and surround it with compost to the top of the roots and at least 3 feet wide.  Unlike most other potted shrubs, blueberries will sink into the soil as the compost around it is worked in by worms, rather than being left high and dry.  

Their spongy root system does not grow deeper than about 6 inches for about 5 years, when they put down a deep taproot for water.  To grow big blueberries before that, run a mister near your plants through the heat of the summer to keep them happy, and always keep their roots covered with coarse bark, straw, or hard leaves that will stick around, like oak leaves or pine needles.   They want full sun and their feet well covered and cool.

         

Rycke Brown, Natural Gardener          541-955-9040        rycke@gardener.com

Crown your Roses to beat Black Spot

Betty Boop, October 2014, after being crowned in the spring.  Note the black spot starting at the base.  This rose is nearly thornless on young parts and blooms all summer into late fall.

When roses are starting to break bud and grow leaves, it is time to crown them, to stop black spot fungus from taking them over and making them pretty flowers on an ugly bush.  The spots are on the stems, and they infect the leaves after they mature.  Removing all the stems, down to the crown, the hard knot of wood from which both roots and stems grow, takes all the fungus off the plant and stops black spot from showing up until fall.

2016 Betty Boop rose, ready to crown.  Note the purple new growth.  It never quite stopped growing this winter.  

         You do not want to crown them in late fall or in winter before bud break, or they won’t grow until months later, as they then feel only the temperature of the soil, and wait until the soil warms up, much later than the air does.  Once they begin to grow leaves, the plant is already growing and cannot stop; it will grow new stems very quickly, though they will bloom no sooner than if you did not cut them.

Betty Boop rose buds breaking red, ready to crown.  Notice the black spots starting.

Some roses bud green.  The black spot fungus grows and spreads all winter.

Nearly all tea roses get black spot in this area, as our winters are not cold enough to kill the leaves or even stop blooming.   The way we were taught to prune roses in spring in Landscape Management class was to wait until the photinia bloomed, to prevent freezing of tender new growth, and cut them down only to a foot tall, cleaning out spindly growth on what is left.  But I found that black spot took over the plant before it even bloomed, as soon as the new leaves were mature.  And roses start breaking bud before the photinia blooms, earlier in recent years, so leaf growth before that point was wasted, and blooming was delayed.

Betty Boop, cut the classic way roses are normally pruned in spring.  

Our teacher taught us that the way to bring any old, ugly shrub back to youth and beauty is to cut it to the ground.  When I applied this to roses, I found that it works for them, too; it grows back beautiful, with no black spot and great blooms. 

Betty Boop, crowned for the third year.  It was about 10 years old before the first crowning, a large, upright shrub rose; trunks 2-3 inches across, the whole crown about 8".

But cutting to the ground is not far enough if the crown is buried.  If you stop at ground level and don’t cut back to the crown, the underground stubs will grow small stems that only crowd the bottom of the plant.  You have to dig down to and around the crown and cut flush with it, filling back in afterwards.  Stems that grow directly from the crown grow back thicker and longer than from stubs, often to their maximum height for that kind of rose.

If that maximum height is too tall for your taste, you can crown it again after the first flush of flowers and it will grow back half as tall and bloom again.  One can crown a rose anytime during spring or summer and may want to if it grows mold on new growth.  But crowning in fall can cause new growth to freeze while it’s still tender and might kill it.

Revised 12-10-24, published online at GardenGrantsPass.blogspot.com  

Gardening is easy if you do it naturally.  Litter is tagging, marking the territory of the disorderly.

Rycke Brown, Natural Gardener          541-955-9040        rycke@gardener.com