Pests in the Rose Garden

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After such a terrible winter, who would’ve figured that we’d have such a quick recovery in the rose garden! Cold, overcast (but mostly rain-free) April gave way to July temperatures in May and June. This warmed up our cold ground dramatically quickly, and hence, our summer scourge of insect pests also arrived early.

Rose Garden Pests

I started spotting Japanese and other Scarab beetles by the third week of June. Usually, they start popping out of the ground around the Fourth of July, evil insect pests that they are!

Another wicked pest in my north central Connecticut garden is thrips. There is no such thing as a thrip, as they arrive by the millions. These pests are so small that I am sure we inhale them as they blow in the wind. Every time I sneeze outside, I am sure it’s from breathing them in! While everyone knows what the beetles look like, thrips are a little harder to identify. You will notice their damage to your blooms before you will ever see them.

Thrips have rasping mouthparts and they know how to use them. They scrape back and forth with those mouthparts and suck up the sap all the while. Your petals will look dirty in spots inside the rose and the edges of the petals will look like they have been singed. If you suspect thrips might be wrecking your blossom, take a lungful of air and blow it into the bloom. The carbon dioxide makes them move around like crazy…sort of like tiny little threads wiggling around at the base of the petals.

You will also notice different color thrips in different colored roses. Some folks think that they go for light colored blooms but this is untrue. They love everything from dark to light but the damage shows up faster the lighter the color of the rose. If you use insecticide in your garden and blast them with a direct hit you will kill them. But, the next day, more will be back in the bloom. This is a terribly frustrating problem, especially if there is a rose show coming up.

Trap Thrips with Solo Cups and Pam

A friend told me last year that thrips are strongly attracted to the color blue, and in California, rosarians paint the outside of blue ‘Solo’ cups with STP. When the thrips hit the cup, they stick and cannot escape. I never tried this last year, but now I’m using a similar method. The picture above is the bottom of my Rose Forest Garden that contains a number of Old Garden Roses that thrive in the afternoon shade and a bunch of other roses, as well. At the base of the garden you will notice inverted blue cups on bamboo stakes. (Someone asked me why the blue cups and I responded, ‘Roses don’t come in blue, so I decided to introduce blue to the garden in this way!’ Only kidding…)

I don’t use STP, however. Every day, I go out with some cheap store-brand version of Pam and spray it on the outsides of the cups. The results are just amazing!! When I set my first cup out, before I even sprayed it, I could see hundreds of pests crawling around on it within seconds! I have probably trapped millions of them by now and guess what? Much less damage inside my roses! I look forward to going out to inspect the traps several times a day to see how many more are stuck to the cups. This gives me a lot of pleasure in a Vincent Price sort of way.

Battle Japanese Beetles with Milky Spore

So now, back to the Japanese Beetles and their relatives. I’m hoping that I won’t have to deal with them for too many more years as I applied Milky Spore Disease last year.

It takes a few years for Milky Spore to get established underground. The beetles pupate from white grubs in the soil which ingest a spore or two while feeding on grass and other roots. The spores begin to multiply inside the grub until there are so many of them that the grub swells and explodes, spreading more milky spore around. (Another Vincent Price moment…I love that visual…)

Milky Spore only affects white grubs, eliminating the beetles in their larval stage. So, until my spores spread around more, I’ll keep spaghetti sauce jars half-full of water with a drop of dish detergent in them, which makes the water more slippery. Then, I’ll hold the jar under the beetles on the bloom, tap the blossom lightly, and the bugs will fall straight down into the soapy water and drown.

I’ve noticed over the last ten years or so that their season seems to be shorter than it used to be…but, that might just be a dream of mine. For the time being, I’m just going to keep that soapy water handy for pests.

Meet Marci Martin

Marci Martin has loved roses for as long as she can remember. From the time she was a little girl, she was fascinated with how…

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