Are you asking for suggestions for other plants with big leaves?

I think Gardener is saying that the Philodendron selloum ( which is planted and overwintered in the ground--not a containerized plant), is developing small leaves. What is the soil like?? They like a rich soil that's high in humus. Are you fertilizing at all? Also, keep in mind these plants like tropical humidity and moderate heat. Extreme Dallas heat and arid conditions this year are not ideal. One more thing, it's also possible that the frigid Winter of 2010 did some damage to the roots (Did you mulch it in the previous Fall? Assuming that growing conditions improve, leaves WILL eventually get bigger and back to normal. As for the Hydrangea--just must be the heat and drought--THEY ARE WATER LOVERS--Their very name means WATER (Hydr-)

When you say your philo came back what do you mean? Do the leaves die off during your winters?

In nature they don't grow like that, they grow year round so if that is the case then they may not be getting enough time to grow so big before the cooler/colder weather hits it and then it needs to start over again.

According to Floridata, the philo is lucky to have survived outside at all last winter. Listed as hardy to zone 9 and above.

When you say your Hydrangea is doing the same thing, do you mean it is dying down to the ground in the winter? There are several kinds of H's. Do you know which one yours is?

With the drought you've been having over there, these 2 moisture-loving plants are probably having trouble just staying alive.

Gardener972,
Soil, soil, soil.
Get your soil tested.
If your soil is poor, dig your plants up and put them in raised beds. Buy pristine soil and use compost and mulch.
It doesn't matter what you plant, if the soil is poor, all your plants are going to look like that.