In the Box:
This weekend marked the Summer Solstice and signs of summer abound here at RTB- birdsong waking us at dawn, a nightly ritual of fireflies rising, lights flickering in the garden and surrounding pasture, and an explosion of plant growth fed by the energy of the sun on this, the longest day of the year.
The diverse explosion of plant life has attracted an equally diverse population of insect life, both problematic and beneficial. The usual suspects are all here, cucumber beetles, flea beetles, and cabbage moth. In addition, this season we have seen an unusual amount of aphid pressure. I typically don’t see much of this pest in the summer and associate aphids as a management challenge that comes along with winter growing in a hoop house. During the colder months biological activity is slowed by cold and dry soil conditions when watering is kept to a minimum to control the increased risk of bacterial and fungal diseases like damping off and downy mildew. However, the resulting decrease in biological activity affects the plants ability to access important nutrients for plant health like magnesium, calcium and phosphorous just to name a few. However, nitrates are highly mobile in the soil and more readily available to the plants. Aphids love nitrogen. My theory is that with the cool dry spring we have been having, biological activity in the soil has been slow and the plants are having difficulty accessing the rich profile of nutrients they need to ward off insect pressure. Fortunately, most of the cultivated crops that have aphid pressure, tomatoes and lettuce, are not yet showing any ill effects. And better yet, the weeds that are hosting the majority of the aphids, lambsquarters, are now also covered with ladybug larvae, a voracious beneficial predator. This week I have given everyone a big drink hoping that some of those excess nitrates will be leached out and the ladybug larvae on the lambsquarters will move over to feast on the aphids living on the tomatoes. A foliar feeding will happen soon to introduce some of those nutrients they aren’t now accessing from the soil. I also hope to get to mulching much of the crops to help retain soil moisture in what’s looking to be a dry season.