February 22, 2016

Avalanche column

February 4, 2016

Aphids, if you garden at some point you will have them. They come with the territory. I have found that row covers create a perfect environment for them. This is the biggest drawback I have found with floating row covers. I do not consider this a show stopper because row covers are so much more beneficial. 

Aphids are very interesting creatures; eggs are only laid by the insects for over wintering. Egg shells are very protective. It is only late in the season that males develop and eggs are laid. The rest of the year, reproduction is asexual and immature pregnant females are born. They are fully mature and ready to immediately start feeding. With this scenario they can quickly get out of hand. Also once the population becomes too great on a host, the aphids develop wings and go find new hosts.

Then to add insult to injury, ants like to farm aphids for the honeydew they produce. Ants will move aphids to new locations for the sole purpose of farming the aphids.

In cool weather the growth of the population is slow but as the temperature rises, they can very quickly multiply and get out of control.

Even if you do not use row covers during the winter, aphids can seek refuge underneath big leaves that are on the ground. Nice and cozy with a “blanket” over they, they continue to feed.

I have used lady beetles to control these guys. They are not the best choice. The first reason is their egg to predator time is much slower than what aphids can do. Inoculating with a mass of lady beetles is usually not very effective because most will migrate upon release. Row covers slow this migration but not halt it. Also lady beetles become dormant in cold weather.

Last year there were some wild Aphidius wasps that cleaned up my spinach just as I was thinking I needed to spray them. This was amazing because they did this during our cool spring. They are most effective with small populations of aphids. Aphidius wasps can be purchased over the internet. I would like to try and use them with an outright infestation to see what they could do. These wasps insert eggs into aphids which cause the aphids to become mummies and thus the next generation of wasps is produced. The mummies look like little off white “balls” attached to the underside of the leaf. They are very effective and the row covers might help “coral” them.

Hand control might work with small infestations. I usually like to use cold pressed neem with a seven day spray cycle until they are controlled. Uncovering the infected beds will also attract beneficial creatures. I have found that a flock of English house sparrows in the spring will clean a bed very quickly. This is probably the only time I sing praise for English house sparrows.

Questions? I can be contacted at markdirtfarmer@gmail.com. Or more garden notes at redwagonfarm.blogsot.com