Saving your own seeds is cost effective and rewarding, however some seeds are harder to save than others. This page looks at the different ways vegetable seeds are pollinated and the relative difficulties of saving them.
SELF POLLINATED (Easiest)
These plants are the easiest to collect seeds from as the seeds will always grow exactly like the parent plant. Plants in this group include Bean, Endive, Lettuce, Okra, Pea and Tomato.
PROPAGATED VEGETATIVELY (Easy)
These plants only propagate vegetatively, meaning that to grow new plants you plant cutting, root, or bulb (depending on the type of plant). Plants in this group include Garlic, Lemongrass, Potato, Tarragon, Tree Onion and Water Chestnut.
PROPAGATED VEGETATIVELY AND CROSS POLLINATED BY INSECTS (Easy)
Propagated by a cutting, root, or bulb (depending on the plant) and will also produce cross pollinated seeds. The best way to propagate these plants is vegetatively. Plants in this group include Asparagus, Chives, Garlic Chives, Jerusalem, Artichoke, Leek, Marjoram, Mint, Rhubarb, and Spring Onion.
CROSS POLLINATED BY WIND (Moderate)
Cross pollinated by wind only, so only cross pollinates with plants of the same variety that are in the immediate area. Plants in this group include Corn and Spinach.
BOTH SELF POLLINATED AND CROSS POLLINATED BY INSECT (Hard)
Will self pollinate, but can also be cross pollinated by insects. Plants in this group include Broad Bean, Capsicum, Chilli and Eggplant.
CROSS POLLINATED BY INSECTS (Hardest)
These are the hardest types of seeds to collect as they can easily crosspollinate with other types of plants of the same species. Plants in this group include Basil, Broccoli, Cabbage, Carrot, Cauliflower, Celery, Cucumber, Fennel, Kale, Kohlrabi, Mizuna, Mustard, Onion, Parsley, Parsnip, Pumpkin, Radish, Rocket, Rockmelon, Silverbeet, Sunflower, Turnip, Watermelon and Zucchini.
* Note that these categories are based on information drawn from a range of seed saving publications. They do not necessarily reflect my personal experiences.
While these seed saving categories are a good guide to work from my experiences of saving seeds does not always match with these categories. Below is a list of some of the vegetables that I have saved seeds from, along with comments on how they fared and where my experiences differ from the above categories.
ASPARAGUS (Propagated vegetatively and cross pollinated by Insects)
I have only ever propagated asparagus vegetatively. This is because: –
- The crowns used to propagate asparagus vegetatively are clones of the parent plant, which means they will be exact copies. Whereas asparagus plants grown from seed may turn out to be quite different from the parent plant.
- Asparagus grown from seed will take three years to harvest, whereas planting crowns only takes two years.
- Asparagus is vulnerable to attacks from slugs and snails when small and asparagus grown from seed is extremely small in its first year.
Unless you are wanting to produce a large number of asparagus plants cheaply it is better to propagate asparagus vegetatively than from seed.
CORN (Cross pollinated by wind)
While corn is listed as moderately difficult to save seeds from it is in fact very difficult when trying to do it in an urban setting as seed from at least one hundred cobs growing on separate plants are needed to be saved to prevent inbreeding depression, a condition that causes new corn to be short and produce few ears. Saving such a large number of cobs is not practicable in an urban setting.
My experience of saving corn seeds was that they had a higher risk of producing infertile cobs. I concluded that it was not worth using saved corn seeds as the risk of inbreeding was too high. These days I only plant bought corn seeds.
CHILLIES AND CAPSICUMS (Both self pollinated and cross pollinated by insect)
While chillies and capsicums will cross pollinate with each other, because they also self pollinate the risk of cross pollination is lower than with plants that only reproduce by cross pollination. But while I have found chillies and capsicums easy to save seeds from, they will eventually cross. When that happens you will have to discard your saved seeds and buy new seed stock.
CARROT (Cross pollinated by insects)
Carrots are considered difficult to save seeds from as they need to cross pollinate with other types of plants of the Daucus carota family to produce fertile seeds. However, I have found it easy to save carrot seeds as they normally stay true to type. Carrots will cross pollinate with other varieties of carrots and with wild carrot varieties (such as Bird’s Nest, Bishop’s Lace, and Queen Anne’s lace). But when I save carrot seeds they mostly stay true to type, and even when cross pollination occasionally occurs the varient carrots that are produced are still good to eat. Occasionally I get the odd small purplish carrot, which would probably be a cross with one of the broader Daucus carota family plants, but such throwbacks are rare.
I strongly recommend saving your own carrot seeds.
MIZUNA (Cross pollinated by insects)
Although the member of the mustard family, which is both large (plenty of varieties to cross pollinate with) and readily cross pollinates, I have found it largely stays true to type, even though it is listed as difficult to save seeds from. So far, all the Mizuna seeds I have saved have remained true to type.
ROCKET (Cross pollinated by insects)
Readily crosses with other members of the mustard family (E.G. cauliflower, broccoli, and cabbage), but because its life cycle is so short it is easy to test its viability without expending much time and effort.
Saving seeds from vegetables that are cross pollinated by insects is difficult due to the risk of cross pollination producing seeds that are not true to type. But there are things a gardener can do to reduce this risk.
- limit the number of varieties of a vegetable that you plant. The fewer varieties then the less chance of cross pollination.
- Plant vegetables in groups of the same variety close to each other. That way when a bee (the most common form of insect cross pollination) transports pollen from one plant to another it is more likely to be cross pollinating plants of the same variety. Grouping varieties works particularly well with vegetables that both self and cross pollinate, such as capsicum, chilli, and eggplant.
- Once you have saved cross pollinated seeds that are true to type use those seeds each year until they are nearing their use by date (this will vary depending on the type of seed). There is no need to save seeds from that variety every year. This is a good practice regardless of the cross pollination risk as, when saving seeds, you usually get enough seeds to last several years.
There are more sophisticated techniques for saving seeds that are cross pollinated by insects, such as covering plants or induvial flowers with insect proof netting and hand pollinating, but I have little experience in these practices.
LEFT: Capsicum that has crossed with a chilli to create a smaller capsicum with a pointed end and hotter flavour, though not as hot as a chilli. It sits next to a normal capsicum. RIGHT: Chillies that have crossed with a capsicum. Their ends were rounded and the flavour milder.