[Weston grower]

This year I planted 11 BNS (Waltham) and 7 Pumpkins (Baby Pam) next to each other. Everything looked good - lots of growth/flowers etc.

However the fruit they have produced doesnt look like BNS or Baby Pam more like marrows. Some are large green marrow shape and others yellow.

Cooked one last night and it was very marrow like.

Is it possible that all of them have cross fertilised and got confused?

Regards, WG

[BabbyAnn]

cross pollination doesn't affect the flavour of the flesh in this season - I often grow different squashes/courgette/marrows/butternut in the same bed or at least close to each other to increase the chance of pollination (got to help those bees find all the flowers!)  As I don't save the seed it doesn't make any difference.

However, if you wanted to save seed to use next year, then yes cross pollination would affect the fruit the following season.

In this particular instance, I'm wondering if you have harvested the BNS too early (normally not ready until at least mid-September or when the frosts hit them in October so I'm surprised you've already tried one)  And not all butternut are "pear shaped" and can look marrow like and green until they start to ripen.  And then they'll need to be cured - not only does this harden the skin to preserve the fruit for storage over winter, but some fruits actually taste better when stored before use.

There is also the weather - without strong warm sunshine, the sugars will be on the low side so will not taste as nice.

[JayG]

Although cucurbits of the same species readily cross-pollinate as far as I know the fruits produced should grow true to type, although the seeds of the fruits will contain the genetic material of both parents so won't grow true to type if saved and re-sown.

Were the seeds straight from a packet or saved from the previous year (and therefore possibly already crossed?)

Edit - seem to be agreeing with BabbyAnn but a bit slower off the mark!

[Weston grower]

BNS seeds were from a packet but the Baby Pam pumpkins were saved from last year.

Both plants are producing fruit that weigh 2 - 3 kilos - real monsters. last years Baby Pams were about 6" diameter and pumpkin shape - as per the packet.

Anyone else having the same problem?

Regards WG 

[A. Fallowfield]

Although cucurbits of the same species readily cross-pollinate as far as I know the fruits produced should grow true to type, although the seeds of the fruits will contain the genetic material of both parents so won't grow true to type if saved and re-sown.

Were the seeds straight from a packet or saved from the previous year (and therefore possibly already crossed?)

I saved my seeds for spaghetti marrow, just to show you're right the first pic is spaghetti marrow the second is on the same plant!

[Weston grower]

Yes thats what the large green ones look like. 

Wouldnt mind but I didnt plant any marrows.

WG

[JayG]

Interesting selection there AF! 

Trouble with unknown crosses is that you don't know what you'll finish up with, and of course F1 varieties are already a cross (albeit a specific one) so will also not grow true from saved seed even if self-pollinated.

It is possible to make sure that a non-F1 variety does set true seed but it does involve getting up early in the morning to catch a female flower when it first opens, hand-pollinating, and then making sure the bees can't get back in to undo your good work before the flower closes and starts to shrivel. 

[BabbyAnn]

Wouldnt mind but I didnt plant any marrows.

WG

ah, but someone else on a different plot may have    Bees do travel far and wide

[A. Fallowfield]

Wouldnt mind but I didnt plant any marrows.

WG

ah, but someone else on a different plot may have    Bees do travel far and wide

I don't grow the large green marrows, but there's five bee hives at the end of my plot!