Why is my Phlox not flowering? Dianthus hybrids seem to do this too!

[newstart]

I have a Phlox which seems to be attempting to flower but then the bud break up or dry out. It is a smaller phlox with small flowers in its 2nd year or so. Could it be over wet causing buds not to develop I sometimes overwater a little? My bigger phlox in same bed seems fine and is even flowering in less than full sun. I do fertilise alpines when they are known to grow bigger ,it helps them fill out in there early years-8 pellets growmore . I then feed a tiny amount once a year when bigger- 5 pellets growmore when bigger. I cannot see any P&D problems but is possible-could be tiny hidden caterpillars eating buds??. I have a sandy loam,more loam than sand. I have a similar problem with Dianthus hybrids which are on a slightly more sandy part??

To be honest I am clutching at straws as I dont really know. Any ideas folks ?and thanks.

[Maggi Young]

I think perhaps the level of feeding you are giving may just be a bit too much in that it is encouraging vegetative growth rather then flower formation.

[Rodger Whitlock]

I have a Phlox which seems to be attempting to flower but then the bud break up or dry out. It is a smaller phlox with small flowers in its 2nd year or so. Could it be over wet causing buds not to develop I sometimes overwater a little? My bigger phlox in same bed seems fine and is even flowering in less than full sun.

Can you possibly identify which phloxes you are asking about? I suggest the following as possibilities: Phlox adsurgens, P. subulata, & P. douglasii.

Overwatering is much less of an issue in the open garden than in pots, because excess moisture just soaks away into the earth instead of being trapped in a pot.

[newstart]

These are the photos of the respective Dianthus(on quite a sandy soil) and the Phlox. Can you identify the Phlox. I had big problems a couple of years ago as non  of my alpines were performing at all. I then added small amounts of fertiliser thinking my loam soil was a little sandy and needed some fertiliser. Sure enough  this worked for the majority of alpines. I think the term is 'bulking them out' when they are to small. It could be the above Phlox is a slow grower(planted it middle of summer last year). It could be it won't flower much on my sandy loam soil or I have slightly gone over on the fertiliser in order to bulk it out. I didnt think id put much on but it could be with slower growing phlox it was to much as Maggie said. The 'odd thing' is it has sent out three or four flowers but the rest seem to produce buds and dry up or not continue the bud formation. What i mean by this is they do start the flowering process and it doesnt materialize.

[Rodger Whitlock]

These are the photos of the respective Dianthus(on quite a sandy soil) and the Phlox. Can you identify the Phlox...

Off the top of my head it looks like Phlox subulata, given the rather lax growth habit. P. adsurgens, usually found in the form 'Wagon Wheel', does not have the needle-like foliage, and P. douglasii (at least as I know it!) has much finer foliage and a more congested growth habit.

However, I have the impression from reading that the cultivars called "Phlox subulata" by nurserymen include hybrids with other species. To call such plants "Phlox subulata" would be a taxonomic heresy, but it's the best name we have for them.

As for not flowering, I wonder if your phlox is not getting enough sun. While P. adsurgens is a plant of open pine woods in semi-shade, Pp. subulata and douglasii  are definitely sun lovers.

I will say that "P. subulata" (whatever it may be) is an easy plant. The garden centres here invariably have a number of different cultivars for sale about this time of year.

About your dianthus I can offer no opinion.

[newstart]

I have a Phlox subulata 'mcdaniels Cushion' which is in similar position west facing which does really well and has slightly less light. It has grown faster with the fertiliser response and flowered. The slower growing subulata with the picture I sent you has more light but the flowers struggle. I think I will have to check the soil it may be a little to sandy. Do you think Maggie is right(see thread) on the fertliser stunting the flowers given it is smaller currently. I did try to cater for it being smaller and give less,its possible I fed twice accidently! I have had very positive experiences of 'better flowering' on my soil with correct small doses of fertiliser(worth mentioning).

Any one else with opinions here?