What exactly does a 'sterile' plant mean ?

I have seen on this forum a few times people mention 'sterile'plants and I an unsure what this means.   Can anyone explain this.

Thanks  

In the usage you refer to, it means that the plant does not produce seeds.  It therefore needs to be propagated by cuttings/layering/division etc. 

Thank you Dovefromabove.   Is the plant still attractive to bees and other insects ?

I understand that most of them still produce nectar so are attractive to bees etc.  

I think some of the problems arise from the complexity of some flower forms which prevent the bees accessing the nectar, and not whether or not the plant is sterile.

Thank you 

Some plant breeders sell plants that either do not have seeds, or from which the seeds will not germinate, so as to keep the plant their property - preventing gardeners from propagating it in that way.  Some very double flowers do not allow bees or other insects to access any nectar they may have - another reason I rarely if ever grow doubled flowers.  

Yes, proprietary plants - created, owned and effectively patented by commercial organisations - usually have sterile seeds to prevent regrowing. Years ago Brocollini - like a miniature brocolli with thin stems and leaves - was introduced into Australia. Its production was licensed to an Australian company by its American commercial "owner" so they were the only source in Australia. You could be prosecuted for even trying to reproduce it.

Hello everyone,

I'm interested in Wallflowers, would the Bowles Mauve & the other perennials types come under the term proprietary plants? I have read that the Bowles Mauve seeds are sterile and that to propagate them you should take cuttings. I have my eye on a "winter orchid" type but can only find plug plants to buy rather than seeds.

I have seen insects on  all my wallflowers & the Bowles Mauve,but agree with Dove & Bookertoo about the  double flower shapes. In my view all plants/insects have developed a particular relationship with each other so that certain species interact with each other. This is the same  for any creature. This has been developed over millions of years. In my garden, some flowers are perfectly designed for a particular insect - the big fat bumblies can open my snapdragons but the other smaller honey bees although they try can not open them to get in. All it takes it one extra strong honey bee to get in..then there is possiblity through genetics for other honey bees to get in.

I think the double flowers are bred with us in mind not the insects. I want my garden to be wildlife friendly.

Don't think Bowles Mauve is a proprietory plant - in fact I'm sure it's not, it's been around for ages, well before plant breeders' rights took off to this extent.    Apparently there are some strains of BM that do set seed, but they won't come true to the parent plant - however you may find a variation that will become as famous and well-loved as it's parent.

http://www.plant-world-seeds.com/store/view_seed_item/2455?actionName=flower_seed_categories&itemname=ERYSIMUM+%27BOWLES+BABIES%27

Thanks Dove for the excellent link, looks like a really good shop