How to growing hydroponic carrots: A full guide step by step: Carrots can be expensive at the grocery store and not very easy to grow in a traditional garden. This article will show you an even easier way: grow them hydroponically!
Carrots are one of my favorite vegetables, but they don’t come cheap out here in the real world; if you buy them from the grocery store chances are they were shipped in from out of state and are not very fresh. If you like to be self-sufficient (and who doesn’t like growing their own food?), you might want to consider growing carrots hydroponically.
Table of Contents
What is Hydroponics?
Hydroponics simply means growing plants with no soil. Instead, plant roots are supported with a growth medium such as gravel or clay pellets. This method of growing is rapidly gaining popularity among small growers because it allows for easier pest control and more effective use of the plants’ root area which translates into healthy, robust plants.
The Best Growth Medium for Hydroponic Carrots
Carrot roots need a fairly large container, preferably with a diameter of at least three inches. Clay pebbles are very porous, so they will likely drain quickly enough for the carrots’ roots to absorb all they need without drowning them. Other popular choices are gravel or sand; however, I have found that these aren’t quite as effective because the fine particles can clog up with soil over time.
I like to use a three-to-one mixture of clay pellets and perlite (which is very lightweight). Perlite holds air pockets which help promote healthy root growth, but also retains water; this means that the carrots will stay moist enough for the roots to develop and not dry out too quickly.
Be sure to sterilize your growth medium before you use it. This is important to prevent root rot and other diseases, but also makes the clay pebbles more permeable by killing off all of the germs that are stuck to them after being mined.
Sterilizing Your Hydroponic Growth Medium
Fill your large mixing bin about halfway with water. Add 1 teaspoon of bleach and mix it in thoroughly. Fill the bin up with clay pebbles until there is about six inches of growth medium at the top of your container. Allow this to sit for 24 hours; after four hours, swirl the contents around to make sure all the pebbles are wetted with this mixture. You can also use a spray bottle to spritz your medium evenly. Drain the water and add new, clean water. Drain again and set the container on its side so it can dry out on a sunny windowsill or in your garden; this helps keep any germs from getting into your hydroponic system.
Hydroponic Carrot growing conditions
Carrots are not very demanding plants. They should do well in most conditions that allow for regular growth, except where the temperature is very hot. The recommended range for carrot growth is between 60 degrees Fahrenheit and 75 degrees Fahrenheit. Carrots also need at least six hours of sunlight per day to grow well, but you can still get a reasonable harvest with less.
Carrots also need plenty of oxygen, so make sure you don’t compact your growing medium too tightly or they may become stunted and deformed.
Carrots will grow best when they receive about one inch of water every week; but, because your medium will absorb most of this, you’ll only need to add more if the top two inches has dried out. Carrots also like their growing medium damp, not wet and soggy.
If you start seeing yellowed or brownish foliage on your carrots, it could be a sign that the roots are rotting. If you aren’t sure what is causing this it may be helpful to set up a small hydroponic system just for your carrots so you can monitor them without disturbing their larger growing container.
Optimal pH for Carrot growing hydroponically
Optimal pH for Carrot growing hydroponically is 5.8 – 6.5.
The Growth Cycle of a Carrot Plant
Seedlings from carrot seeds should appear within seven to ten days after planting if the soil is warm enough. If you plant them earlier, your crop will be smaller but more resistant to pests and disease than carrots that grow over several weeks.
Light requirement for growing hydroponic Carrots
The seedlings should be kept in full sunlight for all this time. If possible, place them where they will receive 6 hours of sunlight each day. If you don’t have 6 hours of direct light available, you can use a grow lamp or fluorescent bulb to supplement the growing area. Make sure that the leaves are sprouting out from underneath the lamp so they also get some light.
Carrots do best when the temperature is between 60 and 70 Fahrenheit. If the temperature drops below 50 Fahrenheit, your carrots will go into dormancy. This means that they won’t die but their growth will slow down to a halt while cold weather persists.
Hydroponic systems for growing Carrots
Carrots are fairly easy to grow hydroponically. You can use a simple system comprised of clay pebbles moistened with nutrient solution.
The easiest growing method is the “Top Feed” method, where your carrot’s roots dangle in a tray of water so you never have to worry about watering them again after the first week.
The “Water Culture” method is also very simple, requiring only a container with an air pump. The roots will dangle in the nutrient solution up to their uppermost leaves, like floating seaweed at the beach.
Carrots can also be grown using either a “Drip Feeding” or a “Deep Water Culture” method.
Carrots take between 4 and 6 months to reach maturity, depending on the type of seed you use (some are slower growing than others) . By this time they should be about 5 inches long. When the lower leaves begin to yellow it is a sign that your carrots will soon be ready to harvest. After this stage it is best to pull them out of the growing medium so they don’t rot in place.
Temperature/Humidity range for growing Carrots
Optimal Temperature: 60° F – 70° F (15° C – 21° C)
Optimal Humidity: 50% RH or higher (lower humidity is okay during cooler days) — If your humidity drops below 40% RH your carrots will become deformed and might even die
If you live in a hot climate, it may be better to grow your carrots hydroponically indoors where the temperature can be easily maintained at an optimal level.
A final note on growing carrots: if you plan to keep them in the same container for more than one month, make sure to leave about half an inch of unfertilized growing medium at the bottom before adding new nutrients. If you don’t, your carrot plants may become too rootbound and will eventually die.
Nutrients for growing hydroponic Carrots
Carrots need plenty of Nitrogen to grow, so make sure you supply your carrots with a nutrient solution that has at least 15% Nitrate (NO3) or Ammonia (NH4)
Carrots also like Phosphorus and Potassium, but don’t overdo it. Too much K can cause the roots to become woody and bitter.
Carrots also need micronutrients to grow properly, so if your nutrient solution does not have a “Total Nitrogen” content of at least 15%, you should add micronutrients so the carrots get everything they need.
