Immature pine cones dropping from my trees

Asked June 5, 2013, 11:52 AM EDT

Can you please help me figure out why our pine trees are dropping small, but brown, immature pine cones and some green cones? (Photos attached) They are about 1 1/2" long, as opposed to the open mature ones that are about 3 1/2" to 4". It's the first of June and we did have a hard freeze the first of May, but I've never seen a freeze affect pine cones before. We live in Alpine, TX and have 24 pine trees. The tops of the trees appear to be loaded with new green pine cones, but the bottom halves to two-thirds of the trees are void of cones. The only information I could find online is to look for gray squirrels who chew them off, but we are not in a gray squirrel habitat area and I haven't seen any squirrels at all here. We have lived here for 3 1/2 years and all that has ever fallen were open brown mature cones. I would appreciate any help you might give. Thank you very much.
Charlotte Travland
Alpine, TX


Brewster County Texas trees and shrubs horticulture

3 Responses

Charotte
Is this happening to all your pine trees? Pine cones or others fruits/nuts fall prematurely from lack of water or inadequate pollination. Pine trees have male and female cones. Male cones are smaller and female cones are larger. Once pollinated, female cones grow the seeds. Some of the female cones take up to 12 months to grow mature seeds. Mature cones will fall from the tree in winter and spring. The female cones on some pine species will open to receive pollen and then close and reopen to fall off the tree or to disperse seeds. The large cones falling may be the female cones pollinated last year. The smaller cones falling may be either male cones that have already shed their pollen or due to lack of moisture in the soil. Although pine tree are pretty drought tolerant. The cones you see at the top of the tree may be new cones or female cones closed after pollination. Every species of pine trees have different growth habits when it comes to cone placement in the tree. Some have male and female cones throughout the canopy. Some have mostly male at the top with females below and some have mainly female at the top the males below. What species of pine tree is this? the picture was not attached.
I am attaching a picture of pine cone pollination.
Logan Boswell is the the Brewster County Extension Agent. Contact him at 432-837-6207

Dotty - I don't know if you received my reply. I was trying to send photos again and it wasn't working.
Thank you for your wonderfully detailed description. Since the pines (I don't know which type) were heavy with pollen and have shed it all, the small cones must be the males dropping now. They have all thinned out as have all the pines in town with this extended drought, but we water them well.
Again, thanks for your quick reply.
Charlotte Travland

Call your county agent. They may know the name of the pine trees. Then you can search for a better answer or I will be glad to help. Bet it is the drought!