Tomatoes, peppers, corn, squash, and so many other edibles come with a list of growing requirements that would be impossible to fill by the maxim "Right plant for the right place". Hybridized for generations by gardeners who would go to any measure for the most plentiful, succulent harvest, most modern fruits and vegetables come with the need for pampering built right into their DNA. The astute gardener knows just how to tweak the growing environment to fit the requirements of each plant, starting with temperature.
Being from the west coast where the growing season begins weeks earlier, I was the first one at my community garden this year to have my vegetable plots weeded, amended and planted. I fussed over the vegetables to make them comfortable, but temperature weighed heavily on my mind. Aside from me being a little early to plant, it was an unusually cold start to spring. I put the three best tips I know for regulating heat to the test. These are them:
1) Water walls for the heat-loving tomatoes. Tomatoes, tomatillos, peppers, squash, peas, beans are all products of pollinated flowers. Only once the plant has been coaxed into blooming and is then pollinated can it transform those flowers into the parts that we eat. All flower buds need a certain amount of warmth to open and for the pollen to ripen. That's where these ingenious water walls come in. I filled the inflatable parts with water and stuck them around three of my tomato plants. The water captures heat when the sun is shining, and retains the heat even after temperatures drop, creating nicely insulated air for the plants.
2) Rocks on the side. Just like the water walls, rocks soak up heat from the sun and that makes the air around them a little warmer. They release the heat so slowly that the air stays warm long after the sun is gone. This helps hasten cell division needed for shoot growth and blossoms, among other things. That's why the plants I grow around the gravel and cement areas of my yard are some of the first to pop up and flower. I extended this idea to my veggie plots and placed rocks (all the ones I found when turning the soil over earlier this season) on the surface of the soil between the rows.
3) Wall flowers. My great uncle always kept a peach tree on the south side of his house. It was stuffed in a small patch of soil between the driveway and the chimney, but somehow it seemed to thrive. He became known through the neighbourhood for handing out large fuzzy peaches at the end of summer, and certainly climbed the list of my favourite relatives for this reason. For a sun-loving plant like peaches, there is no better place to gather heat than a south-facing wall, especially one that is light in colour to reflect the sunlight. If you are in zone denial and want to grow plants that don't usually thrive in your region, get access to one of these walls and you might be pleasantly surprised.
I always knew that water, rock, and southern exposure were great sources of retaining heat, but it's my first season putting that to the test with water walls and rock piles in the veggie patch. I was encouraged by posts from other bloggers like Cohocton River Rock Micro Farm. So far, I have been very pleased with the results! Besides the chard seeds that volunteered to grow between the gravel patio and the concrete pad, my tomatoes are flowering and fruiting prolifically, and my jalepenos came early.
Of course, there are times when too much heat is retained around vegetable plants. Even with the heat-loving plants, it takes some vigilance to make sure that high temperatures are not drying out the soil. Veggies like salad greens, braising greens, radishes and broccoli are getting too much heat when they begin to wilt or flower. Flowering takes nutrients away from radish roots and it's too late to harvest greens or broccoli when they have flowered. Since I planted a whole row of broccoli (my husband is a fan) and I wanted to preserve the flower buds (one of the parts we eat) for as long as it took the plants to become stalky, I shaded them with a row cover made of Reemay cloth. This also helps some of the pests stay off of the plants.
At the end of the day, pampering my vegetable plants with extra shade or heat, extra water, extra food, snipping and tying reminds me of how lovely it is to have other plants that don't need all of this. It's a thought to keep in mind whenever I'm tempted to make new additions to the garden.