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Growing in Your Greenhouse: Leafy/Salad Greens

Growing in Your Greenhouse: Leafy/Salad Greens

Day light savings has officially come into effect and I, for one, am still making the adjustment in the morning time. I did walk my dog this morning by the light of the moon, but, this all means I get the sun shine when I get home from work! Outdoor activities are returning in earnest, people are out starting the tedious process of maintaining a lawn and we all once again need to dust off our sunglasses in order to drive. The sun is shining and what’s more it’s brining warmer temperatures along with it. While it might not be t-shirt weather just yet, we can start toning down how much artificial heat we need to pump into our greenhouses. Yes, we are very much at the point in the year where sunlight duration has reached optimal levels for growing plants, but the temperatures are still a bit too cold to get anything really started outdoors. Luckily for you, that greenhouse on your property can provide your plants safe haven from the strong and chilly winds that accompany March. While not all plants will thrive in the early growing season, cold temperature crops like some leafy greens love this time of year. Not only do leafy greens prefer some cooler temperatures, they tend to grow relatively quick so you don’t have to worry about this crop stopping you from growing a traditional summer garden. Most greens have a timeline from seedling to harvest of about 8-10 weeks. With some careful planning and execution, you could be harvesting your leafy greens just before you transplant your starts for summer. You may need to keep an eye out a bit more for pests and diseases because moisture and foliage generally don’t mix well unless you are trying to generate molds and fungus. Other than that, growing greens should be about as stress-free a gardening experience you can have. So sit back, relax and perhaps you’ll learn a thing or two about growing leafy greens in your greenhouse.

Many people grow salad greens as in-between crops. Essentially this is the idea that you plant a quick growing, minimal effort crop in a space between other crops either where a previous plant was harvested or has died. In this, you can utilize the space without completely throwing off your harvesting schedule. It’s a great way to make sure your space is being used effectively while also providing your diet with some home grown salads! But, if you wanted to grow just salad greens in your greenhouse, the rules change a little bit. Planning isn’t going to be incredible important, but some forethought can help you out in the long run. Actually, the most planning you’ll really need to do is making sure your growing in the shadier parts of your greenhouse as well as sowing seeds far enough apart to ensure they aren’t competing for space as they grow. Now that you’ve got your plan down, you’re basically all set to grow some salad greens.

First things first, well I guess second to your planning, soil is key. Salad greens generally prefer a loamy, rich soil with a high organic material content. Make sure the pH content is in a range between 5.0-6.0 with a salt level below 3500 ppm. Add a comfortable amount of fertilizer, this amount will vary depending on how large of a plot you’re using, mix into the first few inches of your bed of soil. If you are sowing seeds directly into a bed of soil, place a few seeds in holes placed about 6”-12” apart depending on the variety of green. If you are transplanting seedlings, place them in similarly spaced out holes and make sure you water immediately after planting. Most salad greens, lettuces in particular are shallow-rooted and grow at a very fast pace so ensuring they have continuous access to water is vital. Even short periods of drought can greatly impact the quality of leaves which can impact the quality of your dinner. Intense heat and drying out shouldn’t be at the top of your worries when growing in March and April, but that doesn’t mean you can neglect them. If you are noticing your greenhouse is getting a lot of sun and therefore heat, shading your greenhouse and installing a dripper line will make things a whole lot easier. As with any endeavor in your greenhouse, excess moisture needs to be monitored. Wet foliage can easily lead to molds and other diseases to form which can spread very quickly in bed of greens. Using a long spouted watering can will aid you in making sure when watering that the base and roots are getting the water and not just the soil surrounding. A liquid fertilizer added to your watering schedule once every two weeks will help you grow larger and more bountiful greens. Careful not to go overboard with any additional chemicals you plan to use however as the purpose of this garden is to eat. Put good in get good out, put too many chemicals in your plants and you get the picture.

Establishing an optimal micro-climate for your green is essential if you want to succeed. As stated previously, salad greens prefer a colder, less sun intensive environment. To really set yourself up for success make sure your greenhouse ranges between 60-65°F during the day and 50-55°F at night. Higher temperatures will stunt development as will too low of temperatures. Once the seeds have germinated and seedlings have grown, too much heat can burn your leaves. While you may put some sun dried tomatoes in your salads, you probably don’t want burnt greens. Generally speaking, you likely won’t need to invest in artificial lighting. Salad greens don’t need all that much light so what you would spend on the lighting wouldn’t produce sizable enough results to be worth the financial investment. The sunlight available in March should be plenty, and in some cases, too much for your greens. Shading your greenhouse or growing in the shady part of your greenhouse will help you tremendously. Artificial lighting also requires some extra planning as you would have to time when they turn on and off to mimic the natural pattern of the sun. Providing extra sun or elongated hours of light deprives your plants of much needed sleep. Plants tend to reach for the light when it is present so they prioritize vertical growth when receiving light. If they get too much daytime and not enough night, they will be tall, less bountiful heads of lettuce or whatever other salad green you may choose. No one wants weird tall lettuce.

Alternatively, if you’ve set up your greenhouse to run hydroponically, your journey may be even simpler. Start your seeds as you would any crop in your hydro-garden, set the water to flow and feed the system with liquid plant food every week or two depending on how many individual plants you are growing. From this point, so long as your system is working properly with water consistently moving to prevent the water from becoming stagnant, you will have very little to do until harvest. The water tank in your garden will slowly fill with the root systems of your salad greens as the foliage up top grows and grows. In addition to ease of use, hydroponic gardens have been proven to grow plants significantly faster than traditional soil gardens. Of course, as with anything, there are trade-offs. Hydroponic gardens use a lot of water, you need to refill the tank often so the roots don’t dry out. There is also no way to avoid using some form of energy to keep the garden running. There needs to be an active water pump of some sorts, it may not be running all the time, but enough to keep the water from standing still and harboring bacteria. The water and energy bill associated with hydroponic gardens are a reality to the alternative form of gardening. It does, generally speaking, take up less space and grow plants faster but it is not a perfect process.

Growing salad greens is pretty much that easy. It doesn’t take all that much to produce bountiful crops and keep your diet full of salad. So instead of rambling on about something related to salad greens or fun facts surrounding them, I figured I might include one of my passions into this blog and give out some salad recipes!

Candied Pecan, Goat or Feta Cheese and Candied Pecans:

-Mixed Greens

-Dried Cranberries

-Candied Pecans

-Soft Goat Cheese or Feta Cheese

-Raspberry Vinaigrette

-(Option thin sliced red onion)

This salad is nice for a light lunch or optionally add some grilled chicken to make it a larger meal. The sweetness of the candied nuts and dried berries perfectly balances the slightly bitter taste of the greens while the creaminess of the cheese calms the brightness of the vinaigrette.


Mixed Greens with Olive oil and Lemon Dressing

-Mixed Greens

-Dried, minced garlic

-Crispy Fried Onions

-Olive Oil

-Lemon Juice

-Fresh cracked pepper

Completely combine the lemon juice and olive oil, whisking to create a dressing. The garlic and onion give this minimalistic, bright salad a satisfying crunch providing a light but filling lunch.


Taco Salad, Salad

-Greens of your choice

-Grilled chicken strips, seasoned in taco seasoning

-Charred corn

-Black beans

-Thin sliced red onion

-Torn cilantro

-Thin sliced jalapeno

-Sour cream

-Lime Juice



-Crumbled cotija cheese

Welcome to the Taco Salad of your dreams. Mash your avocado and combine it with your garlic, sour cream, lime juice and whatever spices you feel would best accompany your salad dressing (I’d recommend; cumin, paprika, pinch of salt) and blend it all together until smooth. Start with a bed of greens and add all the accoutrement listed above, adding or taking away items as you see fit. Give that all a mix and top with a healthy crumble of the cotija cheese and a drizzle of the avocado crema. This one is a bit more involved than the last two, but trust me it is worth it. Give taco Tuesday a twist with a modern taco salad!


Thanks again to all that read this far! Let me know how you like these recipes, I love cooking and sharing food and recipes with people so this was a very fun blog to write. If you have any ideas for blog topics going forward, leave a comment down below or reach out on one of our social media channels and I’ll be sure to see it! Until next week!


-Brian Bill

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