Thursday, May 16, 2013

Week 2 CSA, Weather or Not

Let’s talk weather.  We’ll get past the sensationalizing of the weather we see in the media talking about scraping your windshield. We are talking about critical aspects of plant growth, and by extension, food production. The crops we grow have varying temperature sensitivities and tolerance to frost and freezing temperatures. We can go to the field with the spring crops mentioned last week knowing they have some tolerance for frost. The normal last frost date for Scott County is May 10, give or take a few weeks. Several years ago, the last frost was April 17 although we did not know that until mid-May passed. The following year it was May 21.  As May begins, we look at long-range forecasts to help us to decide when to start hardening off the plants. 

The plants started in the greenhouse grow at a steady temperature with no wind. They are planted close together in the trays somewhat supporting each other as they stretch out and up with their new leaves reaching for more light. We put the trays of plants on a wagon just outside the greenhouse and let them become accustomed to wind, rain, and cool nights for a week or so. This time of year the daily temperature swings can be 30 to 40 degrees. This will toughen the stem and reduce transplant shock of being placed in the soil, equally spaced apart in the row. If the weather looks like frost we can roll the wagons inside the barn overnight to protect them. 

Frost is a unique phenomenon that occurs when the dew point is close to freezing and the temperature approaches freezing. The ground is warmer than the air and the soil is moist. As the moisture is released into the air (evaporation), aided by transpiration of the plants (transpiration is a plants version of exhaling during respiration), a microclimate near the surface is formed which turns this moisture into tiny ice crystals on the surface of the leaves. Water expands during the freezing process, which ruptures the cell walls on the surface of the leaves, effectively killing the tissue of the plants that are not tolerant of such action. 

We also gauge several other factors in whether frost will form or not, as sometimes the dew point and temperature prediction would indicate frost. If windy conditions prevail, this effectively stirs the layers of air in the atmosphere preventing that microclimate at the surface from developing. The trickier pattern to explain is how cloudy skies prevent radiational cooling at night. Based on the law of physics that for every action there will be an equal and opposite reaction, the earth releases the radiant heat it gained all day, all night. If the skies are clear, this energy is effectively pulled back into space, super cooling the air just above the surface of the earth. Cloudy skies prevent this radiational cooling effect from happening, thus trapping the heat near the surface of the ground.

Farmers talk about frost settling in the low spots. Because these various factors are more likely to occur in low spots versus up on the ridges, we avoid those low areas for the early plantings of sensitive crops. This can actually be a benefit to those same crops if we encounter extreme heat in mid-summer. Also keep in mind, it is generally 5 degrees cooler in the country than it is in town. This has to do with all the concrete and asphalt collecting radiant heat during the day, and moisture not being retained by concrete as it is by soil. Also the cars, industrial heat/air handling systems, and tree-lined streets and yards alter the whole microclimate at the soil level. 

Anytime the forecast is below 37 degrees F, frost is a possibility and we monitor it very closely. Some predictive forecast models called for 32 degrees Monday morning. Thirty-two is a magic number. The water in the plant freezes, the ice formation ruptures the cell walls, end of plant. Nothing we can do. If it is frost, we can spray water on the plants before sunrise, which warms the surface of the leaf with 55-degree water thus avoiding ice crystal formation. We have avoided the temptation to have early crops because of the long range forecast a few weeks ago, but we do have some green beans, sweet corn and early tomatoes out, cross your fingers!

In Your Share

Fresh Asparagus

Bok Choy lovers know to eat both the stalk and the leafy greens, either together in a dish, or chopped and prepared separately. Store refrigerated in a closed container, leaves will wilt slightly prior to the stalk, but it is to be expected and taste will not change.  Long viewed as a specialty item, bok choy is becoming better known and well liked as our menus and palates expand.

Try a simple stir-fry by sautéing some garlic or onion in olive oil or butter; add the chopped white stalks, then a few minutes later add the chopped green leaves.  When wilted, but still crunchy, add a dash of sesame oil.  Enjoy as a nice side dish with fresh garden flavor.

Kale Greens Did you know kale is good for your eyes? It has two carotenoid pigments (lutein and zeaxanthin) that the eye utilizes to filter out some uv radiation. In this way, eating kale can help your eyes protect themselves from the sun’s rays – and hopefully prevent macular degeneration. Lutein levels are highest in dark green leafy vegetables. Kale has the highest amount of lutein per serving than any other green (26 mg/1 cup serving raw, 23 mg/1 cup cooked).  Eat a little fat with the greens to help with lutein absorption (such as olive oil, butter, cheese, nuts).

To prepare for cooking, cut or tear the heavy stem from the leaf.  You can either leave the leaves whole if your cooking time is long enough to let the leaf become tender – or you can cut your leaves into strips for faster cooking.  Kale can be stir-fried, steamed, braised, or oven roasted for kale chips.  

Salad Lettuce



Sweet Potatoes


Recipes to Enjoy 


Aspargus & Creme Fraiche "Crepe" thanks to a CSA member for sharing one of her delicious recipes!

2 eggs

Sea salt and freshly ground pepper, to taste
Butter, to coat the pan
3 spears fresh asparagus, steamed or roasted
2 dollops of crème fraiche
Generous pinch of smoked paprika

Beat the eggs lightly in a small bowl. Season with salt and pepper; set aside.
Melt a thin pat of butter in a small non-stick skillet over medium heat. Add the eggs, and swirl the pan, lifting edges with the tip of a butter knife so any uncooked egg can flow underneath. When the top of the eggs look mostly cooked, add the crème fraiche, sprinkle with the paprika, and place the asparagus on top and. Fold the right third of the egg over the filling, then fold the left third of the egg on top to close the omelet (kind of like the way you would fold a sheet of paper in thirds). Let cook for 30 to 60 seconds more, just until the crème fraiche starts to ooze out. 
Transfer to a dish and serve immediately.

Penne with Shrimp, Asparagus, and Feta
adapted from a Martha Stewart recipe, a timesaver by cooking the shrimp and asparagus with the pasta!

Coarse salt and ground pepper
12 oz penne rigate (ridged)
1 lb asparagus, trimmed, cut into 1-inch lengths
1 lb peeled and deveined frozen shrimp, thawed
3 T olive oil (preferably extra-virgin)
2 T fresh lemon juice
2 garlic cloves, minced
1 C crumbled feta (4 ounces)
¼  C thinly sliced fresh mint leaves (for garnish, optional)

In a large pot of boiling salted water, cook penne 5 minutes less than al dente. Add asparagus; cook 3 minutes. Add shrimp; cook 2 minutes. Reserve ½ cup pasta water; drain pasta mixture, and return to pot.

To pasta mixture, add oil, lemon juice, garlic, and ¼  cup reserved pasta water. Season with salt and pepper, and toss to combine. Gently mix in feta and mint; adjust to desired consistency with some pasta water as needed. Serve immediately.

Sesame Red Curry Chicken with Bok Choy & Sweet Coconut Rice 
Our thanks to a CSA member for this yummy recipe she shared using bok choy

4 C chopped bok choy (1-2 medium large heads)
1 red bell pepper, seeded and diced
1 lb. skinless, boneless chicken breast halves
salt and pepper
½ C chicken broth
½ C sake (rice wine)
2 tsp sesame oil
1 T minced fresh ginger
1 T red curry paste
¼ - ½ C sweetened flaked coconut
2 C rice 
2 (14 oz) cans coconut milk

Arrange bok choy and red pepper in bottom of slow cooker.  Season chicken all over with salt and pepper and place on top.  

In a small bowl, whisk together broth, sake, sesame oil, ginger, and curry paste.  Pour mixture over chicken.  Cook low for 6-8 hours or high for 3-4 hours.  Cook rice in coconut milk.  In a small skillet toast coconut flakes, 5-8 minutes.  Stir toasted coconut into cooked rice, set aside. Spoon rice onto a serving platter, or individual bowls, and top with chicken, vegetables and sauce from crock-pot.

Steamed Kale, kale recipes from Capay Farm Shop
1 bunch kale, rinsed
1 cup water
olive oil or lemon juice

Strip kale leaves off stem and chop loosely. Put into a covered pot and add the water.  Steam until kale is tender, about 5 minutes or to your liking. When done, carefully pour out. Serve kale on a plate sprinkled with salt and olive oil or lemon juice. If you have left over, keep it in the refrigerator overnight. It is great the next day as a ready-made cold salad.

Green Drink
4-5 leaves kale
1-2 bananas (depending on how sweet you like it)
1 apple
2-3 C water

Wash kale, leave stems on. Peel banana, and core apple. Place in high-powered blender with the water and blend. Makes about 1-2 quarts, and best when cold.