This summer I’m going to make sure I collect seed from all the vegetables I grow so I can do it all again next year. I’ve just got to remember to save them from the vegetables I eat in their entirety, like tomatoes and beans. I’ve always collected seed from marigolds, sunflowers, parsley and basil for subsequent seasons (the originals came from my dad’s garden). These plants also self-seed, along with lettuce and “compost tomatoes” which pop up all over my garden (including where I don’t want them).
They are true to type from one planting to the next. 
Many other seeds and shop bought vegetables are produced from hybrids. Hybrids are cross-bred from two plants which were lower yielding and the progeny is higher yielding . Earlier in the year Michael collected and planted seed from a bought capsicum (sweet pepper). A number of plants grew, but they never got very big and the fruit they produced were very small. I left them on the plants because the red against the rest of the garden’s green looked very pretty.
I first planted sweet peas in winter 2006 and collected the seed for this past winter. I forgot that the original seeds were from a chain store packet and probably hybrids. The progeny were slow to get going. They did eventually shoot up, but only had purple flowers. The flowers were pretty, but I missed the combination of colours from the year before. Towards the end some pinks and reds appeared and I’ve decided these hybrid seeds weren’t a total disaster, so I’ve collected seed for next winter. Anthony Leddin, in the Christmas Diggers Club catalogue, said yield decreases in subsequent years , so they might only get worse. I’ll see what happens.
I’ve recently been trying to grow comfrey. Comfrey is a good addition to compost because the leaves are high in calcium, phosphorus and potassium . Its deep roots accumulate potassium  and it spreads rampantly from these roots . Cutting it back for compost helps curb its spread.
The seed packet said the germination rate is 50% so I wasn’t hopeful of success and they haven’t grown yet. After more research I found out that
Russian comfrey will not grow from seed as the plants are sterile. However, propagation is simple enough. Chop off a plant horizontally with a spade and plant all the offsets and roots. Once established, it can be a problem to get rid of as all root cuttings left in the soil will grow. 
I’ll have to keep searching for those root cuttings. The packet of the seeds I got from The Diggers Club said they are Symphytum x uplandicum ie. Russian comfrey. So I don’t know what’s going on.
- Leddin, Anthony (2007) “Explaining GMOs, heirlooms and hybrids” The Diggers Club catalogue, Christmas, p.12-13.
- Taylor, David & Yvonne (1993) The Compost Book. Chatswood, NSW: Reed.
- The Organic Gardener (2006) Growing & using garden Comfrey: the spice of garden compost.
- The Lowdown Zambia (2005) Gardening Galore.