Eric Hsu, a fellow gardener and horticulturist shares his insight regarding mid season tasks for the garden.
Our pace can slacken in midsummer after the spring frenzy of cleaning and planting. Seedlings that needed coddling early on hopefully have matured and beginning to show promises of a late summer harvest. However, vegetable gardening still needs attention until the year’s end as we have a longer growing season in the urban heat island of Philadelphia (killing frost last year did not happen until late November to early December). Below are some of the tasks to be mindful of, not to mention staying well hydrated while doing them!
Once flowers and small fruits form on vegetables, it wouldn’t hurt to fertilize with a gallon of water-soluble fertilizer. I use the mineral-based AlgoPlus 4-6-8 tomato fertilizer for my vegetables since it is higher in potassium, which balances growth and fruit production. This water-soluble fertilizer is not easy to find, but is easily ordered online. A lot of commercial fertilizers can be major pollutants and are high in nitrogen, which encourages leaves at the expense of fruits (i.e. tomatoes, peppers). Overfertilizing can encourage rapid growth that becomes a quick fodder for insects and diseases.
Do not let your vegetables go too long without harvesting – picking means encouraging them to produce more because no energy is wasted in producing seeds. And you want to reap the benefit of having that delicious succulence not savored from supermarket produce!
Beans should be checked regularly – it’s surprisingly fast to see an immature bean balloon into something lumpy and tough.
Squash is best harvested in the morning since plants seem somewhat susceptible to being handling in midday heat. And you avoid having heat rashes from the prickly caresses of the squash leaves.
Picking allows you to see whether successive crops need to be sown for longer harvests (once the summer solstice passes, plants don’t grow as fast as they do in spring). With July around the corner, it’s a good time to think about sowing brassicas (kale, broccoli, cabbage) and salad crops.
Insect Monitoring:
Insects rapidly mature and reproduce during long days and warm temperatures. They will hone on their favorite host plants, which unfortunately includes some of the vegetables we grow.
Those who grow curcurbits (cucumbers, squashes, melons) should watch for cucumber beetles, which transmit cucumber mosaic virus and bacterial wilt. Plants showing cucumber mosaic virus will exhibit irregularly mottling of yellow veins and blotches on their leaves, while those having bacterial wilt will collapse without warning one day. Unfortunately there are no remedies for infected plants, which should be pulled up and discarded in trash, not compost.
Cucumber beetles come in two forms: the striped (Acalymma vittatum) or spotted (Diabrotica undecimpunctata howardi). These devastating insects are usually identifiable by their yellow bodies with either 3 bold black stripes or 12 black spots. I sometimes examine plants in mornings and evenings when the insects are likely to be less active and knock them into a jar of soapy water. In larger gardens, growers will use floating row covers (lightweight spun cloth) to protect juvenile plants from marauding beetles until they flower, or apply organic-approved insecticides.
Eggplants, radishes, and turnips riddled with shot holes and looking undersized have been victims of flea beetles. It is easy to overlook flea beetles, which are nearly invisible to naked eye and frequently active. Look for black dots that jump suddenly among the leaves, and sometimes shaking the leaves will disturb and cause to jump again. Flea beetles tend to favor young, vulnerable seedlings, hence sometimes growers will wait until seedlings reach a larger size before planting them. To minimize the damage next spring, it helps to cultivate the soil and clean the plot of debris in fall. Insecticidal soaps, diatomaceous earth, or pyrethrins can be used at last resort (be sure to read the label carefully before application).
Tomatoes should be pruned of axillary shoots (suckers) that develop in the leaf axils and leaves to a height of six to twelve inches (depending on the variety). The tomato suckers can divert reserves from flower and fruit development. However in the rare episode where a tomato plant is not generous or covered well with foliage, it may help to leave some axillary shoots to shade and protect the developing fruit from sunscald.
While we have been fortunate beneficiaries of rainfall this season so far, we cannot depend on rain alone to grow vegetables well. Last year’s summer drought hopefully taught us that vegetables generally require significant water input to produce good harvests. Watering should be deep and thorough – during heat waves, it’s not enough to use one watering can’s worth for irrigating the plots. On average, I usually use four to six watering cans’ worth of water for my plot, and do watering during early morning and evening when evaporative losses are minimized.
With rain comes weeds, which can grow quickly in our heat and compete with vegetables. They can also harbor insects and pathogens that can affect vegetables as well. Keeping the garden bed free of weeds improves air circulation and sun exposure, lessening the incidence of disease and improving ripening as well. The hygiene extends to pulling out spent or bolted spring crops (lettuce that have turned bitter, arugula that have gone to seed, and cilantro flowering) unless one intends to harvest them for seed.