Last fall I saved seeds from a Delicata squash. I planted about 5 seedlings this spring and the plants grew. However there were 2 different shaped squash – the typical small Delicata squash and then others that were the same colors as Delicata but are shaped more like an Acorn squash. Picture attached. Are they still Delicata squash? The only other vegetable in my garden were some cherry tomato plants.
Thank-you for contacting Toronto Master Gardeners with your question about growing Delicata squash from seed. Unfortunately, your photo did not load correctly so I cannot see what your “new” variety of squash looks like but it certainly sounds like you have a hybridization issue going on.
Delicata squash is a cultivar of the species Cucurbita pepo, which also includes Acorn squash as a cultivar. Delicata was originally developed as a commercial variety in the 1890’s, but became viable on the market in the 1980’s when it was cross-bred with Acorn to improve its disease resistance and yields. Since then it has become increasingly popular. Purchased seeds can be heirloom/open-pollinated, in which case you can collect seed and plant on in the next season; or patented, in which case you are not permitted to collect and re-plant the seed. Open-pollinated varieties tend to come true to type. They have cross-polinated amongst themselves for at least a few generations. In the case of patented seed, you have a first-generation plant and/or squash which will be true to type, but the seeds produced will not usually grow true to type. The second generation plants often resemble one of the parent plants rather than the hybrid (first generation) creation. The expectation is that you will buy seed each year in order to get all of the characteristics bred into the hybrid (see this article on squash hybrids by the University of California Agriculture and Natural Resources for more details on this topic).
If your original plants, grown last year, (or grocery store purchased squash) were grown from patented seed, it is possible that some of the seeds you planted this year have reverted to their Acorn squash grandparent. If the original seeds were open-pollinated, they should have stayed true to type UNLESS the originals were planted in proximity to an Acorn squash plant (last summer). Squash plants cross-breed very readily within their species. These new varieties are no longer Delicata squash, but may be very tasty! If you keep this year’s seeds and plant on again, you may end up with still other crosses. For more information on this topic, take a look at this Article on cross-pollination in A Growing Garden.
I am also providing a link to a useful general article in Gardeners’ Path on Growing Delicata squash.