Melon

Quick growing conditions

How to Grow Hydroponic Melons Indoors

Growing hydroponic melons at home lets you harvest fragrant, ripe fruit straight from the plant. You control nutrition and plant care, and can enjoy freshly picked melons without lengthy transport or storage.

Grow your home melons without chemical pesticide treatments. Choose disease-resistant varieties, keep the system clean and inspect plants regularly. Strong light, suitable temperatures and successful pollination are essential for a worthwhile harvest.

Hydroponic Melon Growing Conditions

These are starting guidelines, not strict limits. The variety, light, temperature and fruit load determine how well hydroponic melons grow and ripen. A plant can remain alive outside these conditions without producing a good crop.

Measure light across the leaves. Kilolux readings are approximate and depend on the white LED spectrum; they should not be applied directly to red-and-blue grow lights.

Choosing Melon Varieties and a Hydroponic System

Choose early-maturing, small-fruited melon varieties suited to your available space and growing conditions. Cantaloupe, Galia and suitable honeydew varieties can be grown under cover. Check the expected fruit size, vine growth and maturity time.

Look for stated resistance to diseases such as powdery mildew or Fusarium wilt. Resistance is specific to the disease and sometimes its race, so check the seed description.

A drip-fed substrate system with perlite suits hydroponic melons. DWC is another option with continuous aeration and sufficient root space. Provide a strong trellis and support each developing melon in a sling or net attached to the trellis.

Hydroponic Melon Nutrient Solution and Care

Recommended Nutrient Profile

All concentrations are in mg/L of the finished nutrient solution.

Source: Nutrient Solutions for Greenhouse Crops, Geerten van der Lugt and co-authors, version 4, 2020, page 47. This is the melon feed profile for inert substrates, with each adjustment calculated from the base composition.

Total N includes both nitrogen forms. P and K are expressed as elements, not oxides. The Cl value means no deliberate chloride addition in this recipe, rather than a requirement for chloride-free water. High water supply means irrigation above 5 L/m² per day. End-of-crop adjustments apply after removing the growing points while the final fruits ripen.

Use this profile as a starting point. Adjust it to your variety, source water, lighting and plant response. Account for nutrients already present in your water.

Use our NPK calculator to calculate fertiliser quantities for your selected profile and water volume.

Check solution level, pH and EC daily. Mix and recheck after topping up. Keep water delivery consistent during fruit development; do not let roots dry out in an attempt to make the fruit sweeter.

Training and Supporting Melons

Train vines vertically to save space. Do not automatically remove every side shoot: many melon varieties produce their fruit-bearing flowers on lateral growth.

Retain suitable fruiting shoots and remove unwanted overcrowded growth. Follow the variety’s training guidance. Keep enough healthy leaves to support fruit development.

For a first indoor crop, retaining one or two fruits per plant is a manageable starting choice. Strong plants and small-fruited varieties may support more. Use an expanding sling beneath each fruit so its weight does not pull on the stem.

How to Hand-Pollinate Indoor Melons

Most melon varieties need pollen transferred to their fruit-bearing flowers. Depending on the variety, these flowers may be female or bisexual. Recognise them by the small melon-shaped swelling behind the petals.

1. Check for newly opened flowers each morning.
2. Collect pollen from an open male flower using a small, soft brush.
3. Gently dab the pollen onto the stigma in the centre of an open fruit-bearing flower.
4. Alternatively, remove the petals from a male flower and gently touch its pollen-bearing anthers to the stigma.

Check daily during flowering: a fruit-bearing flower may be receptive for only one day. Vibration alone is not a substitute for transferring pollen, unlike the usual method used for tomatoes.

Harvesting Hydroponic Melons

Judge ripeness according to the melon type. Many cantaloupes and muskmelons develop a sweet aroma, change skin colour and separate readily from the stalk when ripe.

Honeydew melons generally do not slip from the vine. Look for the variety’s mature skin colour and slight softening at the blossom end, then cut the stalk. Do not force a melon off the vine simply because it has reached its expected size.

Common Hydroponic Melon Problems

• Small fruits yellow and stop growing: Check pollination, light, temperature and fruit load.
• Fruit remains small or lacks sweetness: Check maturity, lighting, healthy leaf area and the number of developing fruits.
• White powder appears on leaves: Powdery mildew is possible. Inspect plants, improve airflow and avoid water stress.
• Plants wilt despite having solution: Check water delivery, aeration and roots. Browning, softness or an unpleasant smell can indicate root damage.

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Sources

• Nutrient Solutions for Greenhouse Crops, Geerten van der Lugt and co-authors, version 4, 2020, page 47