The Quick Guide to Growing Lettuce Hydroponically

This is the first of a series of "Quick Guide" reading materials for crops that have been grown by the owner of GTG through SNAP Hydroponics.

Hello there! For this series of quick guides, each one will have three parts, namely, The Gist, How To, and Everything In Between. Hopefully this is informative enough to ensure success in your hydroponic endeavors. Take note, however, that GTG is not paid to mention or promote a specific brand. You are free to select your own items or inputs.

Lettuce is the recommended crop for starters due to its ease of production. Moreover, it has a relatively quick cycle, compared to larger plants such as tomatoes and peppers. While a cold climate favors its growth, varieties have been developed to allow it to thrive under hot conditions, such as those mentioned below.

THE GIST
Scientific name: Lactuca sativa
Varieties Tested: Lollo Rossa, Green Eton (both from Ramgo), Emperor (Condor Seeds)
Size: Small
Approximate Growth Timeline: [Sowing to emergence: 4 days][Pre-growing: 6 days][Growing at setup: 30-35 days] = total approx. 40 days (Lollo Rossa and Green Eton)
Sunlight: Full, at least 4 hours

HOW TO
1. Get a pinch of seeds. Sow them according to the instructions provided in setting up SNAP Hydroponics. You do not need to bury the seeds; you just have to sprinkle them on top of the coir and water them. Don't allow the setup to dry up; otherwise, it will affect germination rate. Germination time should take around four days.
2. Once the seeds have germinated, water them using dilute SNAP solution (2.5mL A&B per 1L water) until the first true leaves appear. True leaves are the leaves that grow after the first two leaves emerge. This will take around six days from the date of emergence.
3. Around the 10th day from date of sowing, your seedlings are ready to transfer. Pick the best ones in terms of growth and transplant them, one seedling per cup. For one styrofoam box, eight seedlings can be accommodated.
4. Harvest the seedlings at 30 to 35 days after transplant, regardless of its size. You may harvest it earlier but NEVER later, otherwise, you will end up eating bitter lettuce. Bitterness is a result of age, not that it intakes solution.

EVERYTHING IN BETWEEN
1. Most of the time, the setup does not need to be refilled with solution, but in summer times, evaporation rates may be higher. If you see that your lettuce hasn't developed much roots but water has already receded below the base of the cup, all you have to do is just refill it with water. No need to add fresh solution to it. Likewise, if harvest time is near but the setup is about to dry up, just refill it with water only.
2. If you planted iceberg varieties (like Emperor) under hot conditions, don't expect it to form a head. Its leaves will remain loose, and chances are, the leaves will taste bitter. A safe way to ensure good harvest is to follow the schedule of leaf lettuce, such as in Lollo Rossa and Green Eton.
3. It's normal for lettuce to look wilted when the sun is at its peak intensity. They will look fresh once more when the intensity recedes. You should be concerned, however, if they do not seem to recover even at night. If that is the case, then you must troubleshoot it immediately (For now, you may contact us through our Facebook page or mobile number should you have inquiries regarding this matter).
4. Insect pests aren't usually attracted to lettuce, but one must monitor moth larvae (locally known as higad) since they attack lettuce crops. Their population usually increases at the onset of rainy season. Be careful not to touch them by hand since their hair can cause excessive irritation. You may use pesticide, but be sure to pick the right one, and to follow the instructions provided. The label will indicate to which pests is it effective plus the proper way of handling it. You may also contact us for proper guidance.
5. Leaf miners may attack the crops. You can say that they have when you see discolored lines on the lettuce's leaves. They won't kill the plant but it can affect the plants' growth rate if infestation is severe. There is no way to control them by means of pesticide, so the best way to control is to simply pluck out the infested leaves. It is recommended, however, to just leave them alone.

Information provided in this guide are based on the author's experience and on the seminar on SNAP Hydroponics conducted by the Institute of Plant Breeding, UP Los Banos. If you have comments or suggestions, please do not hesitate to contact us.