As an experienced gardener, I understand the importance of knowing how long does lettuce take to grow in hydroponics. Knowing the crop’s life cycle helps you plan for nutrients, water, light, and maintenance. Especially if you are a commercial grower, it is an important thing to know.
In this post, I will address this question and see some related queries like a lettuce growing slowly and how to speed up the growth cycle, etc.
How Long Does Lettuce Take To Grow In Hydroponics?
The time lettuce takes on factors like nutrient balance, weather conditions, and variety. So it is hard to put a pin on the exact time.
However, any lettuce can generally take up to 20-40 days to grow in a hydroponic system. Also, leafy lettuce varieties have shorter growth cycles than head lettuce.
Some varieties, like baby green, have a growth cycle of only 14 days.
To have an optimum growth period, it is important to have the ideal conditions. You can shorten the growing period by providing proper lighting, temperature, the right nutrients, and right pH levels of the nutrient solution.
Why Is My Hydroponic Lettuce Growing So Slowly?
When you are growing lettuce in a hydroponic system, you are already optimizing its growth period, but still, some issues may arise that cause your crop to grow slowly.
Here are some of the issues that may be the reason for your lettuce growing slowly:
1. Leakage in the System
Hydroponics is all about providing the required artificial so that plant grows fast. But if there is any flaw in the system, it will affect the growth rate of the lettuce.
The most vulnerable part of any hydroponic system is the joints and valves that control the water flow.
If there is leakage of any kind, the nutrient reaching the roots of the lettuce will always be lower than you provide. This usually causes undernourishment in the crop.
When the crop is undernourished, it is bound to grow slowly.
2. Improper Lighting
Another reason that slows the growth of the lettuce is improper lighting. This issue is usually with plants you grow indoors under artificial lights.
The color and the duration of the light provided should be optimum which is 10-12 hours of light.
You will learn more about lighting if you learn more about lighting requirements for lettuce.
3. Improper Nutrition
Another cause of slow growth can be due to improper nutrition. Whatever hydroponic nutrition solution you use should be of good quality.
Before using any new nutrient solution on a large scale, test it out on sample crops. Understand how it affects your crop.
From my experience, I advise you to do your calculation while making a nutrient solution. Do not rely on the company instructions that you get on the packaging.
4. Dirty System
Though the hydroponic system has many advantages over the soil, it requires regular maintenance.
Without maintenance, the system accumulates sediments, salt scales, algae, slug, etc.
All these accumulations tend to reduce the efficiency of the system. Due these issues, water used in the system is affected, which in turn affects the growth of the lettuce.
So I advise you to clean the hydroponic system regularly to ensure that the system is running efficiently.
5. Underlying Disease
The lettuce variety that you are growing may be susceptible to disease.
The cause of the disease may be different, but an underlying disease can be a cause for the slow growth of the lettuce.
How can I speed up my hydroponic growth?
Here Let’s see what you can do to reduce the time lettuce take to grow in hydroponics.
1. Increase light intensity
Lights is essential for photosynthesis which helps crops build sugar. By increasing this process, we can increase the growth rate of the lettuce.
How do we do this with light? Do we have to provide light for a longer duration?
No, it does not mean you have to provide light for a longer duration.
You have to provide more light for the required duration only.
For lettuce, you need to provide 10-12 hours of light with an intensity of 400 to 600 μmol·m−2·s−1. So you have to provide high-intensity light for that duration. However, make sure you are not heating the plants with high intensity.
Lights at optimum intensity will ensure that lettuce is growing at the fastest possible rate.
2. More Air For The Roots
Another way to increase the growth rate of lettuce is to provide optimum oxygen to its roots.
The roots of lettuce take up the oxygen dissolved in the water. So make sure your water is well-oxygenated.
You can use air pumps or diffuser tubes.
One technique I have found quite useful is exposing some parts of roots directly to air.
This technique is generally employed in aeroponics systems but you can use a similar technique in hydroponic as well. These unsubmerged roots are called air roots.
However, make sure the root is well moistened. If roots are exposed to air without moisture they will dry out. Dry roots are not good for lettuce.
3. Heated Nutrient Solution
Not many groups think about increasing the temperature of the nutrient solution.
But there was a study done by Horticulture graduate students at Purdue University which showed the impact of maintaining higher temperature.
The study used butter lettuce to test the hypothesis. They used two groups.
One group was subjected to 70/65 degrees F and other at 60/55 degrees F environment, including a heated nutrient solution for 28 days.
The butter lettuce subjected to 70/65 degrees F environment was much larger in terms of leaves as well as weight compared to 60/55 degrees F.
However, you have to bear the heating cost if you want employ a heated nutrient solution.
Whatever crop you grow, make sure you are aware of the growth cycle. It will help you plan your resources as well as maintenance. The Hydroponic lettuce grow time will depend on variety and what kind of conditions you are providing so make sure you keep track of it.