How to grow vegetables indoors on a small budget

Light is the whole question

Everybody starting veg indoors worries about the pots and the mix and the watering, and those are all easy. The one that decides whether you get something worth eating is light, and it's the one nobody looks at properly before they start, so let's begin there.

Go and stand at the window you were planning to use, at about the middle of the day, and be honest about it. A window that gets direct sun on the sill for 6 hours or more is a good window and you can grow a decent range in it. A window that's bright but never gets the sun actually landing on it will grow herbs and leaves and it will not grow a tomato, no matter how well you feed it. A window that faces a fence 2 metres away is a bookshelf.

The mistake is picking the crop first and then trying to make the window work for it. Pick the window first, then pick what suits it, and you'll be eating something instead of watching a leggy plant lean sideways for three months.

What grows in a bright but not sunny spot

Leaves and herbs, and there's a lot more range in that than it sounds. Lettuce, rocket, spinach, silverbeet cut young as baby leaf, spring onions, parsley, coriander, chives, mint and basil if it's warm enough. All of these are leaf crops, which is the point, because a leaf only has to feed itself and a fruit has to be built out of sunlight.

Spring onions are the closest thing to a free lunch, because you can stand the root ends from a bunch you bought in a glass of water on the sill and they'll grow back.

What needs the real sun

Anything that fruits. Cherry tomatoes, dwarf capsicum, chillies. They'll all grow indoors in a genuinely sunny window and they will sulk in a merely bright one. If your window is borderline, a tomato on a sunny verandah or against a north facing wall outside will always beat the same tomato inside, so don't force it just because the plan was indoors.

Pots, and why you don't need to buy any

Anything that holds soil and lets water out the bottom will do. Takeaway containers, an old bucket, a tin, a cut down milk bottle. Drill or punch holes in the base, and put a saucer or an old plate underneath so the water has somewhere to go that isn't the windowsill.

Depth is the only real rule. Leafy greens and herbs are happy in 150mm. A tomato or a capsicum wants 250mm or more, and a bigger pot dries out slower, which matters a lot on a hot windowsill.

The mix is worth spending on, and it is the only thing

Do not fill pots with soil out of the garden. It compacts down hard in a container, the roots stop getting air, and you'll bring in whatever was living in it. A bag of potting mix is the one purchase in this whole exercise that earns its money, and a bag of seed raising mix on top of that if you're starting from seed, because seed raising mix is finer and it lets a small seedling get going.

Seed is the cheap part. A packet of lettuce or basil seed gives you months of sowing, where a punnet of seedlings gives you one go.

Watering, and how people kill them

More indoor plants die from too much water than too little. Push a finger into the mix up to the first knuckle, and if it's dry down there, water it. If it's damp, walk away. Water until it runs out the bottom rather than giving it a splash, then tip out whatever sits in the saucer, because a pot standing in water is a pot with rotting roots.

A windowsill in summer dries a small pot out fast, so check daily in the heat and every few days when it's cool.

Feeding

Potting mix has a bit of feed in it and it runs out in about six weeks, and after that the plant is living on whatever you give it. A liquid feed every couple of weeks through the growing season is enough for leaves and herbs, and a fruiting plant wants it more often once it's flowering.

On the kitchen scrap tricks, be realistic about them. Eggshells and banana skins break down very slowly and they're not a feed, they're a slow soil improver at best. Coffee grounds are fine in small amounts and they will go mouldy in a pot if you pile them on. Put them in a compost bin if you have one, and feed the pots with something made for it.

Start small

Three pots of something you'll actually eat beats ten pots of a project. Herbs are the ones that pay off fastest, because a supermarket bunch of coriander costs real money and a pot of it on the sill keeps going for months.

Shop related products

• D.T. Brown Sweet Basil seed. One packet is a whole season of sowing.
• D.T. Brown Curled Parsley seed. Slow to come up and then it keeps going for ages.
• Brunnings Premium Potting Mix 36L. The one thing worth buying properly for indoor pots.
• Neutrog Seamungus Liquid Concentrate 1L. A liquid feed for once the mix runs out of nutrient.

Did you know we also stock lettuce, spinach and shallot seed and seed raising mix in the garden centre that aren't all listed online, so give us a ring on (08) 8536 4333 to check what's on the shelf.

The seed rack, the mixes and the pots are all in the garden centre, and if you tell us which way your window faces we'll tell you what'll actually grow in it.

More from the patch

• Tips for growing fresh herbs in your backyard
• The five most beginner friendly vegetables to grow
• The hidden trick to growing perpetual spinach year round

I am the person who buys the coriander anyway because I forget to sow the next lot, so do as I say on that one rather than as I do.

Cheers,
Candeece

Follow our Facebook page: Strathalbyn H Hardware