As you plant cucumbers, squash, and melons you may think about the possibility of these plants cross pollinating and producing fruits with off flavors or some bizarre new fruit you would not want to eat. Have no fear, the fruit from these plants will all be just as expected in regard to appearance and taste. Yes, some squash may cross pollinate with other squash but the fruit will not be effected because it has the genetic material of only the plant that produced it, that is, the plant that you put into the ground. The seed is another matter. It is a product of the pollination and may contain genetic material from two different plants. If they are unrelated, any plant that grows from that seed will reflect the genetic make up of both parents, for better or worse.
Cross pollination will make a big difference to gardeners who like to save the seed for next year’s garden so lets take a look at what kinds of melons, squash, and cucumbers will cross pollinate. The key is to take notice of the species name of the plant (that’s the second word of the botanical name). Members of the same species can cross pollinate but members of different species can not. Here are some of the common kinds of squash, melons and cucmbers you may grow.
Group A Cucurbita pepo:
Yellow crook or straight neck
Gourds and many other ornamental types.
Many pumpkins including Cinderella, Big Tom, and Connecticut Field.
Group B Curcurbita moschata
Group C Cucurbita maxima
King of the Mammoths
Group D Cucurbita mixta:
Tennessee Sweet Potato
Group E Cucumis sativus:
All slicing and pickling cucumbers EXCEPT:
Group F Cucumis melo:
Snake cucumber or Serpent melon
Group G Citrullus lanatus:
The key to this whole thing is the group in which a plant belongs. Members of the same group can cross pollinate; the fruit/vegetable will be as expected but the seeds may not produce the offspring you expect. Plants in different groups do not cross pollinate so fruit/vegetable and seeds will be as expected and the seeds can be collected and used to produce new plants. If you want to grow plants in the same group and have reliable seed you can do so but you will have to grow the plants ¼-1 mile apart depending on the species!