When to Harvest Lettuce
This is potentially the most important aspect of harvesting lettuce. You can cut lettuce many different ways and obtain a harvest. If you fail to pay attention to when you are harvesting, you could lose your crop. Lettuce has thin, supple leaves that wilt quickly if drained or deprived of moisture. Ever wonder how stands at the farmers market keep their greens looking crisp and fresh through a long hot day? It’s all about the timing.
Most home gardeners aren’t harvesting large amounts for storage or sale. If you plan on picking greens just before you eat them, then pick them anytime. Avoid picking in extreme heat and dryness, the leaves could wilt before they reach your plate on an especially hot day or if they need water.
If you want to store your harvest for any length of time, you must get up early. Farmers will harvest lettuce crops between the wee hours of 2 a.m. and sunrise. One rule of thumb states: pick lettuce before the dew evaporates in the morning. This time of day is when the lettuce plants are at their most crisp, cool, and bursting with moisture. This rule is the same for all lettuces whether leafy or heading. Greens like kale are a bit hardier, but still typically harvested before the heat of the day sets in.
How to Harvest Leaf Lettuce
There are many methods for harvesting lettuce plants. It depends on the type of lettuce you grow, what type of harvest you are looking for, and what you plan to do with the garden space. If you don’t need the space right away, plant loose leaf lettuce and let it regrow all season. One harvest isn’t enough for these resilient plants. Another name for them is ‘cut-and-come-again’ greens.
They always look great in the garden, spilling out of their row or container in looseleaf bunches. Leaf lettuces include things like:
- Green and Red Leaf Lettuces
- Oakleaf Lettuce
- Mustard Greens
These greens are perfect if you are strapped for space in the garden. Just plant a couple of successional rows or beds, then return to these areas every other week for harvesting. You can harvest leaf lettuce at any stage: microgreen, baby-leaf, or mature. Typically gardeners allow it to reach 4 inches tall before cutting. This ensures it has a strong root structure.
When the plant is ready for harvest and at the desired size, take a pair of sharp scissors and cut the greens. Cut them above the main root system, about an inch from the soil surface. If you damage the root system the plants may die. Do this in the early hours, and immediately plunge harvested greens into an ice water bath. Let them soak for 20 minutes to an hour before taking them out of the bath, drying them off, and placing in plastic bags for storage in the fridge.
Within two to three weeks, your plants in the garden should have a new crop ready for you to cut. Loose leaf lettuces are supposed to be harvested this way, though the method works for any type of lettuce. Heading lettuces will re-grow, but they won’t produce heads the second time around and too much cutting will cause them to bolt.
How to Harvest Head Lettuce
Lettuce varieties are on a spectrum from looseleaf to crisphead. There are loose heading lettuces which produce relaxed leaves in a type of head. There are open headed lettuces with form heads that are open at the top giving them the appearance of looseleaf. Then there are crisp heads like Iceberg and some Romaine varieties. These lettuces form the closed ball or elongated head that we picture in the supermarket.
With any lettuce variety, the outer leaves can be picked and eaten throughout the season. The plant will continue to put out more leaves from its center. Butter heads are typically harvested this way, by just picking off the outer leaves and leaving the center to grow.
Harvest crisphead lettuces when you can give the heads a light squeeze and it doesn’t collapse under the pressure. Using a sharp knife early in the morning, cut the head off of the base at the stem about 2-3 inches from the soil surface. Plunge the heads into an ice water bath for up to an hour before drying them and storing them in plastic in the fridge.