Can watermelon plants be grown indoors?

[CookingWithGas]

Not necessarily for the fruit. My daughter wants to do something with watermelons for a science fair project (required for her 9th grade biology class). The fair is in Feb and normally watermelons can’t be planted until after the last frost. I have found lots of information about growing them in a home garden, but nothing about growing them indoors.

For purposes of growing several plants in different kinds of soil, can this be done indoors with an October planting, perhaps with plant lights to augment natural window light?

She would be monitoring the health of the plants. I don’t know jack about biology so I don’t know whether they could even bear fruit without being pollinated by bees, etc. So it might not be possible to compare the fruit of the different plants.

Just trying to find out if this can be done, because it would really suck to spend 3 months trying to grow plants for a science project and end up with 20 pots of bare dirt.

[Mangosteen]

Its certainly possible, but you are going to have to set up a rather expensive lighting system.

Make sure your plants are only a couple of inches from the grow lights.

[WhyNot]

Does it have to be watermelons? There have to be a dozen more kid project indoor friendly plants out there…

[Squink]

Watermelon vines get quite large:

Watermelon vines require considerable space. Plant seed one inch deep in hills spaced 6 feet apart. Allow 7 to 10 feet between rows. After the seedlings are established, thin to the best three plants per hill. Plant single transplants 2 to 3 feet apart or double transplants 4 to 5 feet apart in the rows.

Start the seeds inside 3 weeks before they are to be set out in the garden. Plant 2 or 3 seeds in peat pellets, peat pots or cell packs and thin to the best one or two plants. For expensive seedless types, plant one seed to a pot or cell and discard those that do not germinate. Do not start too early - large watermelon seedlings transplant poorly.

Perhaps Eggplant or Okra instead?
If she wants something exotic, Cherimoya seeds from the produce aisle start quite easily.

[CookingWithGas]

@WhyNot

Does it have to be watermelons? There have to be a dozen more kid project indoor friendly plants out there…

Yes, her class does a lot with arabidopsis. But she wanted to use watermelon <sigh>

[purplehorseshoe]

As a general rule of (green) thumb, vegetable plants need full sunlight. That means hours and hours of direct, full-on sunshine. Tomatoes, corn, squash, melons … they all need lots of sunlight. You can’t artificially provide that, indoors and in the wintertime, without significant $$ for grow lights. On top of that, as Squink pointed out, watermelon vines sprawl out into huge plants, even the more compact “bush” varieties like Bush Sugar Baby. Sorry, but she’ll have to find something else.

Maybe a cold-tolerant winter veggie like spinach or Swiss chard? (The “Bright Lights” variety of chard is easily available, grows easily from seed, and comes in beautifulneoncolors.)

[dracoi]

It might work if she designs the science experiment to be something suitable. I agree with the others that getting a healthy adult watermelon plant indoors is just not practical. But she could do a science experiment to, say, study the effects of soil temperature on seed sprouting and seedling growth. If grow lights were needed in that kind of experiment, it would only be for a couple of weeks, and you’d never need to support a full-size plant or wait for them to fruit.

[CookingWithGas]

Thanks for all the input. She met with her teacher, and her teacher put her on a different track so we’re no longer looking at growing watermelon plants. <phew>:cool: