Oh my…the weather is ABSOLUTELY FANTASTIC! I guess we are being rewarded for putting up with the horribly unbearable summer we have had. 
Everyone seems to be excited to get outside and make everything beautiful for autumn. At Suburban, the mums and many other bits of fall color are pouring in the doors (and flying back out). We are also gearing up for our fall festivities which will include visits from Cowgirl Kate and Witch Hazel! I hope you and your family will come out and see us, you will have a great time!
There are so many things that can be done in the yard at this time of year: aerating and seeding, laying sod, cleaning beds, trimming shrubs, planting bulbs (later), preparing tropicals to return indoors, installing new plants and cleaning and/or dividing perennials. This is the best time to
Not only that, you have a larger window to work with. Hostas, Daylilies, Liriope and Iris are all perennials which benefit from being divided every few years. Sedum should still be divided in the spring since it is just getting ready to bloom. Liriope is easy to divide but you might wait until they are nearing the end of their bloom cycle.
Hostas can be divided in two ways. I usually “shave off” sections that I wish to move elsewhere. Using a sharp shovel, it is simply a matter of cutting a section of the plant away. Usually it is best to try to retain the shape of the original plant. The other method is to dig the entire plant and cut it into sections, each of which can be replanted. Dividing Hostas will also insure that your plants will bloom the following year. When disturbed in the spring, they will occasionally sulk and refuse to bloom during the initial year.
The picture below depicts a hosta which I would consider in need of division.
If Daylilies get too crowded, they will begin to produce fewer blooms. It is necessary to give them some elbow room every few years. Enthusiasts of these plants insist that the best way to divide them is by placing to pitchforks/garden forks back to back through the center of the unearthed plant and then prying the roots/tubers apart. This does less damage to the plant than cutting through with a shovel. A clean division will help the plant establish easier and make it less open to diseases or pathogens in the soil. When dividing your Daylilies, you will want to cut the foliage down to a manageable height, keeping in mind that the foliage is what nutrients to the roots. Try to remove only what is necessary to keep the plants from flopping over onto the soil. 
Green foliage that comes in direct and flat contact with the soil will invite slugs and other pests, rot and other problems. Daylilies love sunlight and will bloom profusely if they have enough of it. Be sure to find a location which will be easy to water in a time of drought, too. While the drought will not kill them (generally), they will go dormant, turn brown and become very unsightly. Consider spacing, as well. A small clump of Daylilies will quickly take up quite a bit of space. A bit of forethought will save you the work of moving them before you would have needed to.
This is also the ideal time to divide or plant Bearded Iris and others. They are not the easiest plant to correctly install in the ground, but I hope to relay the important factors to you. The first thing you will want to do is to cut the foliage down about half way (leave about 6-8 inches). I cut mine at an angle with a point in the center, but it shouldn’t matter.
The next thing to think about is placement. Bearded Iris are rhizomes which seem to grow “backwards” and this year’s rhizomes are finished blooming. The offsets produced by this year’s rhizomes will bloom next year. If you visualize the rhizome as a “foot”, it will be easier to place them taking into consideration the fact that they will spread “backwards”.
The new rhizomes (next year’s blooms) will appear near the heel. The other important step is insuring that the top of the rhizome remains slightly above the soil level, exposed to the sun. If planted beneath the surface, they will not perform well, probably won’t bloom and may even have weak foliage.
You may have to check on them periodically to make sure they haven’t fallen over. If you have landscape fabric staples, they can be pinned into place. Installing Iris properly will insure gorgeous blooms for years to come!
Above all, have fun in your gardening adventures and remember:
Ornamental grasses did not even skip a beat which was of no surprise, but other plants which I was sure I might lose impressed me. My fear of losing many was generated by the fact that
I was surprised about was Ninebark ‘Diablo’ (on right pictured with Dianthus flowers). At around 6 feet tall, my plant has been in the ground for about 5 years now. Displaying only minor symptoms of being sprayed, this plant also received very little heat scorch despite being in a 100% full sun area. There are two Barberry bushes to either side which have lost quite a few leaves.
the new growth which appeared soon after barely even wilted during this heat spell. The feathery wands stood tall and proud. I will be adding more of this to the garden next year.
Lilies took a beating (all appreciate cooler weather), the 
fragile. They barely even survive our zone and can sometimes be difficult to establish. All three of my plants still look as healthy and strong as they did before the heat wave hit. They are even blooming! 
In addition, all of my Caryopteris ‘Summer Sorbet’ and Baptisia australis (pictured to the right) also sailed through this wave…they had already finished flowering which helped.
