Tag Archives: cool

Do You Prefer It Cold or Hot?

Heat loving peppers

Heat loving peppers

One of my first lessons in growing veggies is to learn the plant’s preference for temperature. To keep it simple, there are cool season and warm season crops. Getting to know what the plant prefers determines when to buy/plant, what to buy/plant, where to buy/plant, and when to harvest/eat! In the mid-Atlantic area, typical cool season plants are anything in the cabbage family (cabbage, broccoli, collard, Brussels sprout), lettuce, pea, kale, chervil, dill, cilantro, leek, scallions, radish, spinach, arugula, beet, pak choi or bok choy, carrot, mustard, parsnip, turnip, and Swiss chard. Some can carry on during the summer such as spring onions and Swiss chard; others “bolt” as soon as it warms up in May/June. For example, cilantro will “bolt,” that is, flower and go to seed, as it warms which is good if you want the seed but bad if you want to harvest the leaves. When the plant bolts and goes into flower/seed production stage, the leaves tend to taste bitter.

Most people associate the warm season edibles with summer itself, fresh tomato and basil, eggplant, pepper, corn, summer/winter squash, zucchini, melon, watermelon, cucumber, okra, and pumpkins.

The idea is to plant the cool season plants/seeds in mid-March – beginning of April and the warm season plants/seeds in early May – end of May in my zone 7 area. Several good ways to figure this out:
Read the seed packet or label
Read seed catalogs
Research on the internet
Read local gardening books
Visit garden nurseries and ask knowledgeable staff.

Most catalogs put their plant/seed offerings in alphabetical order but really it would be useful if you read them in order of the calendar year. My 2014 Botanical Interests catalog has “warm season” or “cool season” to the right of each plant type, making it very easy to identify. I have often thought that it would be better to cut out the pages of the plants I was interested in and re organize them to place them in order of season, not alphabetical, as a way of determining which to should start first. Then I discovered that the Botanical Interests web site allows you to sort the veggies by warm or cool season – very smart of them!

The three books I found most useful books for determining a time table are:
The Week-by-Week Vegetable Gardener’s Handbook by Ron Kujawski & Jennifer Kujawski (Storey Publishing, 2010)
The Timber Press Guide to Vegetable Gardening in the Southeast by Ira Wallace (of Southern Exposure Seed Exchange (Timber Press, 2013)
The Year Round Vegetable Gardener by Niki Jabbour (Storey Publishing, 2011)

Cool Season Veggies/Herbs in Containers

2014Aprilgarden 007

scallion seedlings

Around St. Patrick’s Day, I start the cool season veggies and herbs from seed in containers on the deck. You would be surprised at how easy it is to grow lettuce, cilantro, or scallions in small containers with little depth. It is best to use plastic as opposed to terracotta during cold weather but any container with drainage holes will work. I have used old Easter baskets, straw baskets, wooden crates that once held tangerines (lined the large gaps), and recycled plastic plant containers from the nursery.

2014Aprilgarden 011

spinach seedlings

You only need about 6 inches to grow lettuce, spinach, cilantro, kale, red radishes, arugula, chives, and the Asian leafy greens such as tatsoi and mizuma. Except for the radish of course, which is a small bulb like root, these plants have fibrous root systems that do not extend too far down into the soil. The actual plant is fairly short so the plant won’t topple over in a small container. If you have a larger container with more depth, say 8 inches, you can extend the possibilities to baby carrots, scallions, small onions, chard, broccoli raab, pak choi, chervil, and parsley.

Fill the container with potting soil, making sure you have drainage and aeration, sprinkle a few seeds on top, lightly cover with soil (read seed packet about this), water, and place in a sunny place. Bagged potting soil never has enough aeration for me; I always add perlite (the small white pellets) to increase aeration. To deter squirrels, I sprinkle blood meal on top of the soil. Blood meal is what it is: dried, powdered animal blood, typically from cows. Fortunately, it is not red; it is a black powder that contains a small amount of nitrogen (which is beneficial for the plants). The smell deters squirrels but it has to be re-applied after heavy rains. My pots are on the deck for easy access but they could be on the ground as long as they are in the sun and near a water source. Don’t forget to put a label in the pot and record what you planted (I am a big advocate of keeping records and writing everything down).

The key is to keep an eye on the weather. It’s okay if the weather gets too cold because these are cool season plants but it is not okay if the seeds are allowed to dry out. Once the seed absorbs water, germination begins, the seed coat breaks open and the root grows out. If the seed does not get water anymore, it dries up and the germination process ends and cannot be “re-started.” So always imagine the top inch of the soil where the seed is and know whether it is moist from rain or your watering can. After you can see an inch or so of green, imagine that the root has sunk down a few inches and can draw up the water that is in the middle portion of the soil. Now imagine the middle portion and ask yourself if it needs water, that is, has it rained recently? Where I live in Northern Virginia, once the plants are growing, I can usually count on the rain to keep them well watered in the spring.