Growing Hydroponic Squash and Zucchini

Hydroponic Squash and Zucchini
Difficulty Light EC Range pH Range: Time to Harvest
Hard 16 hours 1.8 to 2.4 5.8 -6.5 4 months
Nutrient and Health Info -Reasonably good source of vitamin C, B1 and B6.
Tips & Tricks - Plants may need to be tied to a trellis as the fruits become larger. Plant dwarf or smaller varieties. Hand pollination is usually required. Plants will flower early, but must become mature to produce fruit. Flowers are delicious to eat. Harvesting young smaller fruit encourages flower production. Plants can get quite large, so plant in bottom row of the iHarvest.


Here’s an interesting fact, all zucchinis are squash, but not all squash are zucchini.  Both of them can be called squash.  There are summer squash and winter squash.  Pumpkins are an example of winter squash.  Summer squash are referred to as Zucchinis.

Generally speaking, zucchini (summer squash) is harvested while still young and soft, while winter squash are harvested later in the season, when fully grown and rigid.  More on that below.

Squash is rich in vitamins A, C and K.  Many types of squash are high in carotenoids as well, which can be great for your eyes and your heart.

A word of caution – Squash requires a bit more patience to grow than many other fruits and vegetables.  If you’d like to grow it, you are likely to have more success if you’ve already experienced growing cucumbers and eggplant.


Squash grows well from seed.   Consider using our Seedling Starter Kit, or using the paper towel method for best results. You can also sow your squash seeds directly in the iHarvest®, although propagation may be slightly slower and less successful.


Give your squash plenty of light for them to grow successfully.  Like all fruit, squash performs best when receiving 16 hours of artificial light.  This ensures that your plants will flower frequently, and your plant has enough energy to produce mature fruit.

EC Range:

Your iHarvest® comes with an EC tester.  EC stands for ‘Electrical Conductivity’ and it is a measure of the nutrients in your water solution.  When growing squash, you will want to keep your EC range between 1.8-2.4 for optimal growth.  Squash grows great with other plants that grow well in these PPM ranges, such as bell peppers, celery, swiss chard and spinach

pH Range:

Your iHarvest® comes with a pH tester.  Adjusting your pH allows your plants to absorb the nutrients they need, as efficiently as possible.  Keep your pH between 5.8-6.5 for optimal growth.


Squash is a flowering/fruiting plant.  When they are young, before they begin flowering, your squash will thrive with a general nutrient mix for vegetation, like those that have an N-P-K ratio of approximately 10-5-14 like IGWorks® provides in its Green Machine Nutrients.  When your squash begins to flower and fruit, they will do better with a nutrient solution that has more Phosphorus (P), like our Flower Power Nutrients.  Add 50% Flower Power nutrients to your mix when your plant begins to flower.   By adding the flowering mix to your reservoir, you will get more squash to fruit, and they will ripen faster.

An important note on Potassium (K):  Squash flower prolifically, and flowers require potassium.  If your cucumbers are having trouble setting fruit, or the fruit aborts quickly, they may have a potassium deficiency.  Consider adding 1/4 teaspoon of a 0-0-50 nutrient mix for every 10 gallons of water in your system to help your squash flower, fruit and grow.  Keep your total EC range between 1.8 and 2.4


We created a special section for this article, because squash tend to mature more slowly than many other fruits.  Like cucumber, the first flowers that you receive will be male flowers, and this process can last longer for squash than it does for cucumbers.  Female squash flowers will appear to have a baby squash growing under them, whereas male flowers do not.

Mature squash leaves will often develop a silver color on them.  While it is important to be aware of the possibility of powdery mildew, it will more commonly simply a symptom of age.  These are natural patterns which generally mean your plant is maturing as it should (it may even produce more fruit at this stage).  As plants get more and more silver, it may be a sign that they are aging and will ultimately produce less fruit.


Squash do take up a lot of space with their leaves, so keep that in mind if you choose to grow them.  As your squash vines begin to outgrow the space you have for them, you can prune them by taking off old or damaged leaves.


Most squash is not self-fertile.  Make sure your female flowers are pollinated frequently in the early stages, so that fruit will be more likely to set.  Using a small art or makeup brush to pollinate with is a great idea.  People also love electric toothbrushes.  We have a whole article dedicated to pollinating your plants here.


Winter squash are ready to eat when the skin hardens.  You can tell by pressing your fingernail against the skin, and confirming that it does not pierce easily.  Pumpkin is a great example of a winter squash, although it has an even more firm skin than most.

Summer squash should be picked when small and soft.  As it matures, it will develop more and more seeds, while also becoming more watery.  Picking summer squash early will leave your plant with more energy to grow even more summer squash.

Time to Harvest:

Plan on harvesting your squash ~4 months after you’ve planted seeds, and you won’t be disappointed.  It may take less time, especially when managing your nutrients, pH and EC as described above.


Remember, you don’t require a green thumb to grow in the iHarvest®.  The more closely you follow the directions, the more squash (and zucchini) you will have.  And don’t forget, IGWorks® and the Indoor Garden Works Group on Facebook are always here to help.

Check Out Our Squash and Zucchini Recipes!

Let's grow together!