How to save seeds in the autumn garden

Seeds you can save from your garden
  • When pulling out spent summer crops, you may like to consider saving some of the seeds for sowing next year. The value of saving your own seeds is they adapt to your environmental and climatic conditions and the plants grow bigger and stronger every subsequent season.
  • You can however only save seeds from open-pollinated crops. An open-pollinated plant variety is one in which pollination is carried out by wind, insects, or other naturally-occurring agents. The seed saved from an open-pollinated variety can be grown in subsequent years and will breed true, providing it doesn’t cross-pollinate with another variety of the same species.
  • An example of this is Rob planted Lebanese cucumbers this year, thinking he’d save the seeds, but mistakenly he planted Apple and Telegraph cucumbers in the same bed. Most likely they’ll have cross-pollinated, so the seeds from the Lebanese cucumber won’t be true-to-type. The same applies to pumpkins, which are open-pollinated. If you find pumpkins growing in your compost heap, they’ll have cross-pollinated, and the result will usually be inedible.
  • You can’t save seeds from hybrid plants, which have F1 or hybrid on the seed packet. Any seed produced by F1 plants is genetically unstable and can’t be saved for use in following years. Not only will the plants not be true-to-type, but they will be considerably less vigorous. If you use hybrid plant varieties, you have to purchase new seed every year.
  • The professional seed savers isolate their beds of each family of plants from one another. Bees can fly up to 2 kms and cross-pollinate crops. Due to the impracticality of separating crops this far, seed savers will often use pollen cages which are covered in a fine mesh. The weave of the mesh or fabric must be small enough to prevent insects or pollen (depending on whether the plant is insect or wind-pollinated) from passing through.
  • There are four groups of plants that Rob saves seeds from each year: beans and peas; the solanum family which includes tomatoes, eggplants, peppers and chillis; lettuces; and flowers.
  • It’s important to harvest your plants for seed saving at the right time. Beans have to be plump and slowly changing to a yellow-brown colour before harvesting for seeds. If you leave them on the vine for too long, they can become susceptible to bean weevil. See here for how to save bean seeds.
  • Tomatoes are ready for seed saving when the vine starts dying, when they’re completely red and even dropping off the vine. See here for how to save tomato seeds.
  • Eggplants are ready for seed saving when their skins lose their glossy sheen. Save them as you would for tomatoes, since the seeds are deeply embedded in the flesh, like tomatoes.
  • Harvest peppers for seed saving similarly, when they’ve lost the sheen on their skins. Cut open the pepper, take out the seeds and dry them on a piece of kitchen towel for 2-3 weeks, then pop in a ziplock back, label and date them, and store in the fridge.
  • Rob saves his flower seeds for the insectary because they’ve adapted to his conditions and produce such vigorous plants. The only thing you can’t guarantee with flowers is that they’ll reproduce with the same colours. But then that’s the beauty of nature at work.
  • When the flowers start drying off, pick a bunch, tie the stems together and hang upside down. When the flowers are completely dried out, you’ll be able to shake the seeds into a container and save in ziplock bags in the fridge.
  • Root vegetable crops are more tricky to gather seeds from. Carrots and parsnips cross easily, so the seed you save may not result in an edible vegetable. Beetroot crosses as well, but at least the vegetable will be edible, even if not recognisable as a particular variety of beetroot. Save beetroot seeds as for flowers, by hanging the seed heads upside down in a bunch, which, when dried, you can shake into a container.
  • Fruit trees will grow from apple and pear pips, but they readily cross with other apples and pears, so any offspring will more than likely be different from the mother plant. The problem with this is that it can take 5-6 years for the tree to mature and produce, and it may only be then that you find out whether the fruit is tasty or not.
  • Plums are not genetically stable either, and the resultant tree may also not bear tasty fruit.
  • You can grow fruit trees from the stones of peaches and apricots however. Dry the stone somewhere like a windowsill (but not in full sun) for 2-3 weeks. Then put it in a vice and crack it open to get the kernel out. You can use a hammer, but take care not to damage the kernel. Place the kernel in a ziplock bag with some sand and leave in the fridge for 2-3 weeks. A root will emerge from the kernel. Pot the seedling up till the plant is big enough to put in the garden.


Camera: Lachlan Justice
Editor: Nathalie Nasrallah
Camera equipment kindly loaned from the Department of Performing and Screen Arts, Unitec