I've designed and worked in edible gardens in a range of urban backyards with all sorts of space restrictions. Some compete with tree roots, others are impacted by the shade of neighbouring houses or trees.
Building raised beds in the sunniest spot in your garden is a great option for space-restricted vege growing. Use untreated macrocarpa sleepers. Line the interior with heavy duty clear polythene around the inner edges (not the base) to increase the lifespan of the timber. Build the bed at least 1m wide and up to knee height.
The addition of a mobile planter or two means you can side-step the shade. Add wheels to planter boxes so you can move them in or out of the sun, depending on the season.
Make use of vertical spaces and narrow areas down the side of your house to grow runner beans, peas and tomatoes.
You can train cucumbers and pumpkins to grow vertically too.
The community gardeners at our environment centre have a small allotment each and make use of all available space. They plant corn for runner beans to climb up and squash as a ground cover (this trio are known as "the three sisters"). Last year a pumpkin vine rambled through the boundary shrubs and provided the unusual sight of a pumpkin perched in the Tahitian lime tree.
Seed sowing tips for a budget-friendly vege garden
Trays, punnets or pots ... ?
Most veges (apart from root crops, baby leaf crops and species with large seeds) are better suited to being grown in punnets before planting into your garden.
• Use seed-raising mix for best results. With very fine seed combine with sand or seed-raising mix to space more evenly, then sow. Cover with a thin layer of sieved mix to the depth recommended on the packet.
• Gently water with a fine rose on your watering can. Cover with clear plastic and keep moist in a warm, sunlit spot. If the surface of the seed raising mix is damp to touch, you don't need to water.
• Once germination occurs and some "true" leaves have appeared on your seedlings (not the first "seed leaves") the seedlings can be transplanted into larger pots or directly into the garden if they're strong enough.
• Harden your seedlings off for a few days by leaving them in the sun before planting into the garden. Daily watering is important while the seedlings establish. Remember to apply pet-friendly snail bait.
Potted veges ...
When growing veges and leafy greens in pots, add some organic fertiliser to the lower half of the pot before sowing to ensure your plants have the nutrition they need. Alternatively, water with liquid fertiliser every week. Ensure your pot is a good size to reduce the risk of the soil drying out. Terracotta pots should be coated with a sealant to reduce water loss.
Root crops ...
• Unlike other vegetables that can be grown in punnets, root crops resent being transplanted. Sow directly into the vege bed.
• Pre-soak beetroot and other "corky" seed types before sowing.
• Ensure you have finely prepared soil. Mix carrot seed with half a bucket of seed raising mix or sand to help with spacing.
• Mix radish seed with carrot seed when you sow - radish are faster to germinate and will provide a crop well before your carrots. Press with your hand so the seed has good soil contact and keep moist.
• Cover with a single sheet of newspaper to prevent the soil surface drying out, and remove once germinated.
• Cover freshly sown seed with bird netting to prevent black birds digging the lot up.
• Avoid using rich compost on root crops - you will get forked roots and very lush tops.
• Pull baby carrots and nibble fresh or steam as a side dish in a fancy dinner. You'll help thin the main crop and get the ultimate homegrown treat.