There is sometimes a very fine line between an ornamental plant and edible plant. Scarlet runner beans have always been grown for their pretty red flower, as well as for their flavorful beans. A more recent one is ‘Emperor Runner’. Those pots of colorful miniature peppers that were quite popular for many years at Christmas and the pepper “Black Pearl” that was developed specifically as an ornamental are both edible as well as attractive. The novelty Easter egg plant is a type of white eggplant. The ornamental sweet potatoes come in lime green, purple and tri-color leafed varieties. These are all vegetables that are grown primarily as ornamentals.
A second trend in the genetics game has been to develop vegetables that are used primarily for eating purposes but are so colorful that they could easily be grown as ornamentals. ‘Bright Lights’ Swiss chard is a combination of red, yellow and green stalks topped by dark green curly leaves. New this year is ‘Red Magic’ Swiss chard, which has vibrant red stalks and leaf veins. Cauliflower now comes in at least three colors other than white. ‘Graffiti’ is a dark purple and is full of anthocyanin, which is a strong antioxidant. ‘Cheddar’ is an orange
variety that carries 25 times more vitamin A than the white variety. There are a number of different green cauliflowers, ranging from pale green to the brilliant lime green of ‘Trevi’. The Romanesco variety of cauliflower looks like a fanciful pyramid and adds a bit of whimsy to the garden.
The lettuces that are currently available are in a field by themselves. There is a huge variety of colors and leaf shapes. The loose leaf lettuces are probably the most decorative. I call these the “cut and come again” lettuces as they can be cut off at ground level and they will grow back just as lush. Meanwhile, the gardener can dine off of the cuttings. ‘Red Sails’ is an heirloom and All-American Award Winner. It is a nice burgundy and green color that darkens as it ages. The clumps can grow to a foot in diameter . The oak leaf lettuces have a very distinctive leaf shape; a long pointed tip with a wider base. ‘Navara Red’ combines a red leaf with a green base. One of the reddest of the reds is ‘Revolution’. The catalogue describes the leaf as “frizzy edged” and recommends it for flower borders.
For a ferny vegetable look to mustards such as ‘Mizuna Red Streaked’ that is crimson and green. ‘Mizuna Lime Streaked’ has deeply serrated
leaves that are a green streaked with lighter markings. Like lettuce, mustards bolt so they are only suitable for spring cultivation. Eat them early or they get too strong.
Along with the tendency to breed pretty vegetables we are seeing more miniaturized vegetables. These are described as patio vegetables and suggested for small gardens or pots. There are lots of small beans that never get bigger than 18-24 inches. ‘Pickwick’ is one that has pretty red flowers. It can be found at Thompson and Morgan. ‘Cherry Falls’ is a tomato that was specially bred for baskets. It has a cascading habit and produces cherry type tomatoes. ‘Tumbling Tom’ is another one with the same growth pattern that produces yellow tomatoes. There are miniature eggplants, peppers and even a miniature pumpkin (‘Summer Ball’) that can be grown in a pot.
So, put them together and what have you got? The answer is decorative planters that you can eat. The addition of some annual flowers takes these pretty pots out of the vegetable gardening category and provides interest and color while the vegetables are past their prime or are maturing. Those spring lettuces are going to bolt and you may be cutting them for salads but if you grow them with pansies the pots will still be attractive. Put in a few ‘Bright Lights Swiss chard for height and the result is a charming spring planter.
A summer planter will need at least 6 hours of sun and the vegetables chosen should be those that mature later in the summer. Perhaps a bronze fennel, mixed with cascading tomatoes, some mini-peppers in multiple colors and orange marigolds for that sunny spot near the front door. Or maybe a ‘Graffiti’ broccoli, purple basil, parsley and white cascading petunias for a cool summer look.
If you decide to try one of these mixed gardens choose as big a pot as you can find. A larger pot will be easier to keep watered, as vegetables require even more water than flowering plants when grown in containers. Good drainage is essential since the planters will be subjected to natural rainfall. Placing an upside down pot in the planter will keep the drainage holes from clogging and will save on soil. Use rocks or Styrofoam peanuts in the bottoms of the pot to improve drainage.
There is not set type of soil to use in outdoor containers. Most books and articles advise using a light soil mix with vermiculite or pearlite, peat moss and a good potting soil. If you have no intention of moving the pot, you can use a mixture of compost and peat moss. The pot will be much heavier than with store mixes. The peat moss keeps the compost from clumping and improves the drainage. Sand can also be added to improve drainage. Since these pots are outdoors regular top soil, mixed with peat moss and compost can be used.
Even large pots will need frequent watering. Watering will leach the nutrients from the soil, so the plants will have to be fertilized. A slow release fertilizer can be worked into the soil when the pots are planted. When flowers start on the vegetables a liquid fertilizer can be added for maximum production. Remember that fertilizers with high nitrogen content will promote lush green growth but will not encourage flowering or the production of fruit. Save the high nitrogen fertilizers for your lettuce and spinach.
We are going to be trying some of the mixed vegetable and flower pots this summer around town. Linda actually got tomatoes at the library last summer from a volunteer tomato that turned up in one of the pots. I pulled the tomatoes out of the pots on the Pershing Lot but they kept trying. We both used compost that was full of tomato seeds. This year we will make the tomatoes welcome. If you are interested in what was done on a large scale at the Chelsea Flower show last year check this link. http://www.bbc.co.uk/chelsea/show-gardens/2011/m-and-g-garden-bunny-guinness.shtml