Tired of reading the news and wondering if what you’re eating is going to make you sick? Want to avoid Spinach E. coli and get on with your life? Then, grow your own spinach and lettuce and eat with confidence!
It’s super easy, because spinach and lettuce are straightforward to grow, and with better indoor lighting available, you can have leafy greens all the time.
For people in really cold areas we’ll discuss growing spinach and lettuce indoors, and for those people in more moderate climates we’ll discuss direct sowing right into the garden for a great fall and winter crop.
Let’s go over some general growing information first, and then we’ll get into specifics about how to sow and grow spinach and lettuce indoors and then specifics about how to grow spinach and lettuce outdoors.
Fall is the best time to get started, because spinach and lettuce, like endive, Swiss chard and carrots, are cool weather crops.
Spinach and lettuce can be sown by seed, which is available at any garden center, or online catalog. They do better when sown now, in the late summer or early fall. Both like temperatures around 65 to 70 degrees (18-21 C), although lettuce can take even cooler weather.
If the seeds get too hot, 80 degrees (27 C) or warmer, they will not germinate, or if you have plants already growing and it gets hot, they will bolt and go to seed really fast. Lettuce can be a bit more tolerant, because hot weather varieties are available, so keep this in mind when looking at and evaluating your growing environment.
When growing indoors you’ll have to monitor your environment a bit more closely, so pay attention to your indoor day and night temperatures and the amount of light available.
Most leaf crops like spinach lettuce, endive, and Swiss chard require cool indoor temperatures. A bright room, or an enclosed, sunny porch where temperatures will not dip down to freezing, would be a good place to them. These plants will tolerate daytime temperatures in the low to mid 60’s (15.5 C) and can take cool nighttime temperatures down into the upper 30’s (1.11 C).
Light intensity is also an important factor to consider, because indoor light is very different in late fall to early spring. The days are shorter, but the plants will still require 6 to 8 hours of sunlight. The first thing you might want to do is place the plants right next to a window, but don’t! The problem with tender plants is that they are susceptible to the cold that radiates from the windows during the coldest part of the year, so keep them back a bit.
Indoor soil requirements are also going to be a bit different. For indoor vegetable gardening, stay away from what we traditionally use and recommend: rich soil with lots of compost.
Instead, use lightweight soil mixes. They drain and breathe better. A good mix for indoor vegetables would be 1 part potting soil, 1 part vermiculite, 1 part peat, and 1 part perlite.
Water the spinach and lettuce as needed. They both like to be kept evenly moist, but not wet, so try and allow it to dry out a bit between watering because you don’t want them to rot. Also, because you are watering plants in a pot, you will need to fertilize a bit more than you would outside. For best results, feed every two weeks and use a balanced organic fertilizer like a 15-15-15 or a 20-20-20.
Lastly, when growing spinach and lettuce indoors, pests that are common to houseplants can be attracted to vegetable plants. These include whitefly, spider mites, and mealy bugs. Treatment would be the same as for houseplants, and insecticidal soaps are very useful to have on hand. Read all labels carefully and make sure they are safe for edibles!
Indoor Growing Specifics:
Leaf crops can have deep roots so pick a container that is 10 to 12 inches (25.4 – 30.5cm) deep that will allow those roots to grow.
Sow seeds directly into your container, or you can use lettuce seedlings from the nursery. Because spinach doesn’t transplant as well as lettuce, you’re better off direct sowing the spinach seeds.
Because you will be growing this indoors, I would pick a couple of varieties of spinach that are more resistant to diseases.
For crinkle-leaf (savoyed) spinach choose:
For smooth-leaf spinach choose:
Since lettuce is a bit tougher, just about any variety will do, ‘Buttercrunch’ is always a favorite.
Mix some soil. A good mix for indoor vegetables would be 1 part potting soil, 1 part vermiculite, 1 part peat, and 1 part perlite.
Plant spinach seeds � inch (1.3 cm) deep. Spinach seeds germinate best in soils around 65 to 70 degrees (18 – 21 C). Germination takes 7-14 days.
Plant lettuce seeds 1/8 inch (0.3 cm) deep. Lettuce seeds germinate best in soils around 40 – 65 degrees (4.4 – 18 C). Germination takes 7-14 days.
Once germinated, thin spinach to one seedling every 3 inches (7.6 cm) and lettuce to one seedling every 6 inches (15.2 cm).
Both leaf crops need even moisture throughout their growing season, so monitor it fairly closely.
Both leaf crops will need 6-8 hours of bright light. A bright room or an enclosed, sunny porch where temperatures will not dip down to freezing is a good place to place your pots. If needed, get a few grow lights to help supplement your plants. They are super easy and fast to set up.
After your seeds have germinated and you have thinned your plants, feed every two weeks and use a balanced organic fertilizer like a 15-15-15 for best results.
Spinach and lettuce are ready to harvest when the leaves are big enough to pick.
Harvest by either cutting the leaves away from the plant or by pulling the entire plant out. Leafy crops benefit from cooling immediately after harvest. Wash the leaves in cold water.
Spinach and lettuce leaves are quite perishable and are normally eaten promptly, but they can be stored up to 10-14 days in the refrigerator. Spinach freezes well, so you can always consider that option.
Spinach is sensitive to ethylene gases, so do not store it with fruits and vegetables that produce ethylene gas, like apples.
Outdoor Growing Specifics:
If you live in an area that gets moderate temperatures with no hard frosts, you can follow many of the same steps as above to grow spinach and lettuce in the fall, early winter, and early spring. If you might get some warm weather, then look for heat-resistant varieties that will do better and not bolt.
Steps for Outdoor Growing:
Choose a site that gets full sun in cool weather and partial shade in warmer temperatures. Soil should be light, fertile and moisture-retentive, with a pH of 6.0 to 7.0.
Dig in plenty of compost to ensure the right soil conditions and to provide the nitrogen necessary for good leaf production.
Sow seeds directly into the garden, or you can use lettuce seedlings from the nursery. Because spinach doesn’t transplant as well as lettuce, you’re better off direct sowing the spinach seeds.
Plant spinach seeds 1/2 inch (1.3 cm) deep and 3 inches (7.6 cm) apart in wide rows, and lettuce seeds 1/8th inch (0.3 cm) deep, and 6 inches (15.2 cm) apart. For a continuous harvest, sow every two weeks while cool temperatures allow. This way you will get a staggered harvest that lasts longer.
Thin seedlings to 6 inches (15.2 cm) apart when the plants are 4 inches (10.2 cm) tall. Be ruthless; crowded plants are more likely to bolt and go to seed prematurely. You can always use the cuts in salads.
Keep the soil moist, and feed plants every 2 weeks until they’re 6 inches (15.2 cm) tall.
Mulch established plants to conserve moisture and deter weeds.
Cut spinach and lettuce leaves as you want them or harvest entire plants when they reach maturity and before they begin to flower. If you see buds starting to form at the center, cut the whole plant immediately.
Growing your own lettuce and spinach is a snap, and I really hope you try it out.
It tastes great, and the neat thing about growing leafy greens indoors or out, is that you can grow more than 1 crop if you want, so you can have weeks of harvest to enjoy your efforts.