Whether you have a spacious patio to work with or just the corner of a fire escape, you have plenty of room to get growing with container gardening. From flowers to food, you can get started with some of these basic tips from Lori Metz, who is part of the Master Gardener Program with the Penn State Cooperative Extension, a resource for free gardening guidance.
This is somewhat of a chicken-and-egg question. Do you choose your plant first, or your container? While you can grow in almost anything that holds soil, there are a few things to consider when deciding what kind of container you need. Concrete isn’t always attractive, but it insulates well and won’t blow over, so it can stay outside year-round. Plastic containers can look just like terra cotta and they’re lightweight if you need to bring a plant in from the cold, but they dry out more quickly. If you’re working with a flashy or frilly plant, a simple container will accentuate it well, while a really beautiful container shows best with more modest contents.
As with any veggie plant, buy disease-resistant varieties, remove dead leaves to keep the plants healthy and don’t put them outside before the last frost—temperatures below 40 degrees overnight. Look for vegetable plants that are marked bush, compact, dwarf or patio. You want a tomato plant that will grow to a manageable two to three feet rather than ten! The concept of Thrill, Spill and Fill applies to growing edibles as well as flowers. You can grow several plants that use the space in different ways in the same container, especially as some plants mature later in the season. There’s plenty of room around a little tomato plant for lettuces, spinach, radishes and things you can harvest quickly in the time it takes for the tomato to shade everything out by midsummer.
Consider the purpose of your container. Do you want cooking herbs close at hand? Are you connecting an indoor room with the patio by decorating the view through the window? Are you going to define an area, control the traffic on the deck or just draw attention to a focal point? These are all possibilities with containers.
Be sure to put plants that need the same amount of sun and water together. No one would plant a cactus with a water lily! Less obviously, begonias and geraniums may look great together, but begonias prefer shade while geraniums prefer sun. Where edibles are concerned, most plants need at least six hours of light per day, and most prefer full sun. That being said, it’s also important if you bring a plant home from a greenhouse that you don’t place it out in the sun right away. Plants that are used to being in warmth and safety can go into shock outside and need to be hardened off. Start by taking them outside on overcast or rainy days so they can adjust to the growing conditions.
The confined environment of a container tends to dry out fast, so you have to be conscientious about watering. Keep soil two inches from the top of the container to leave room for some mulch that will keep soil moist and stop water from running off onto the ground. Make sure your containers drain really well, because overwatering and soggy roots can be as dangerous to plants as drying up. Water the soil rather than the foliage, which can encourage mildew and disease, and don’t skip watering just because it’s rained—the foliage can block rain from getting to the soil. Hanging baskets have a tendency to really dry out, so they can benefit by occasionally soaking for 20 minutes in a bucket of water.
Garden centers have different potting soils and mixtures for different plants, but if you want to make your own, a mix of one part peat moss, one part perlite and one part compost works well for most plants. Steer clear of using a shovelful of soil from your yard to avoid organisms or insect eggs that could be harmful, or rogue weed seeds.
7. Plant Fertilizer
When you put a plant in the ground, it can reach whatever’s under its roots, but once a plant grows enough in a container, it uses up the nutrients around it, so fertilizing is important. There are options like granule fertilizer beads, organic fish emulsion or blue water products. Some people use a half-strength every time they water, and some people add it every two weeks. How much you want to spoil your plants is a matter of personal preference.
Lori Metz Master Gardener Program Penn State Cooperative Extension Northampton County: 610.746.1970Lehigh County: 610.391.9840extension.psu.edu