As a brand new, organic gardener, I am very inexperienced. What way to gain experience, than to have things go wrong – and thereby, hopefully, learn from your mistakes? In this case, the squash, zucchini and cucumbers went horribly wrong in the span of a couple of weeks. My inexperience didn’t catch the invasion of aphids in time, and the plants are now almost dead because of it. My last update on these plants – exactly three weeks ago today – showed healthy plants that were beginning to form blooms. I wasn’t exactly happy with the small amount of foliage at that time, but I wasn’t really concerned about the plants. It wasn’t until another week later that I realized something was wrong.
Of course, I had to do research on aphids to understand how they work, what they do, what problems they cause and how to treat them. Aphids generally do not need much control, as beneficial insects naturally gravitate towards infestations and clean them up naturally. In my little garden, however, things have been so dry and there isn’t much local vegetation around to attract beneficial insects, that I don’t think the ladybugs even knew to come on in. I should have purchased some, but by the time I realized I should, it was already too late. The aphids can reproduce rapidly, feeding on the young tender leaves and flowers of their host plant. Their tiny mouths pierce the plant, drawing out the aphids food and leaving behind a sticky sweet substance called honeydew. The honeydew is a food for other insects – some beneficial, some not so beneficial – but in this case, sugar ants moved in. The ants and the aphids formed a symbiotic relationship. The ants tend to the aphids because they produce the ants’ food source – honeydew – and actually help cultivate the young aphid larvae so that they can grow into adults to produce food. I watched sugar ants moving up and down the plants, crawling carefully over the aphids, to feed on the undersides of the leaves and the base of the flowers.
Aphids are a common vector for disease. As they pierce the plants, they can transmit the mosaic virus, which can have a devastating effect on t host plant. I think this is what happened to my squash, zucchini and cucumbers. The first sign was yellowing leaves and slowed growth, then the leaves starting curling under, turning dry at the edges. The leaves started developing dry spots on them and any and all new growth came in curled, malformed and died very soon. As you can see from the pictures below, the devastation is nearly complete on the cucumbers. I pulled up a squash and zucchini plant about a week ago because they were all but dead. I knocked off the aphids with a strong stream of water then treated them with worm casings tea, but the disease had already taken hold and I fear there is no turning back now.
my poor, suffering zucchini
see the very small, curled new leaves that aren't maturing
yellowed leaves with spots and dried edge; small, stunted, curled new leaves that never mature
although flowering, the leaves are yellow and curling with spots and holes
a larger view
a different view
you can easily see the remains of aphids on the underside of the leaves
Pretty gnarly, huh? I hope that I can spot and prevent future infestations from taking over the rest of my plants. In the meantime, I think it’s probably a safe bet to go ahead and order ladybugs, which I will release in stages. As for these beds, I need to decide if I want to plant anything else (options are limited this late in the game) or simply amend the soil and have it prepared for early spring planting. Perhaps I can use these beds as an overflow for lettuce/spinach/broccoli. We’ll see about that…