Sunday, November 29, 2015

Oakleaf Hydrangea, A Four Season Shrub

Double flowering form in mid-May
There aren’t many plants that can look good in all four seasons. One might say that an evergreen plant would be such a plant, but that seems like cheating. 

Our native oakleaf hydrangea (Hydrangea quercifolia) manages to look good year round, even when it doesn’t have leaves! This is the time of year that I really appreciate it.

Oakleaf hydrangea is native to the central and western parts of Georgia. It was discovered in 1775 by William Bartram as he travelled through Crawford County, Georgia. 

His journal included a sketch and these words: 

NEXT day we travelled about twenty miles farther, crossing two considerable creeks named Great and Little Tobosochte, and at evening encamped close by a beautiful large brook called Sweet Water, the glittering wavy flood passing along actively over a bed of pebbles and gravel. The territory through which we passed from the banks of the Oakmulge to this place, exhibited a delightful diversified rural scene, and promises a happy, fruitful and salubrious region, when cultivated by industrious inhabitants, generally ridges of low swelling hills and plains supporting grand forests, vast Cane meadows, savannas and verdant lawns.
I OBSERVED here a very singular and beautiful shrub, which I suppose is a species of Hydrangia (H. quercifolia.) It grows in coppices or clumps near or on the banks of rivers and creeks; many stems usually arise from a root, spreading itself greatly on all sides by suckers or offsets; the stems grow five or six feet high, declining or diverging from each other, and are covered with several barks or rinds, the last of which being of a cinerious dirt colour and very thin, at a certain age of the stems or shoots, cracks through to the next bark, and is peeled off by the winds, discovering the under, smooth, dark reddish brown bark, which also cracks and peels off the next year, in like manner as the former; thus every year forming a new bark; the stems divide regularly or oppositely, though the branches are crooked or wreathe about horizontally, and these again divide, forming others which terminate with large heavy pannicles or thyrsi of flowers, but these flowers are of two kinds; the numerous partial spikes which compose the pannicles and consist of a multitude of very small fruitful flowers, terminate with one or more very large expansive neutral or mock flowers, standing on a long, slender, stiff peduncle; these flowers are composed of four broad oval petals or segments, of a dark rose or crimson colour at first, but as they become older acquire a deeper red or purplish hue, and lastly are of a brown or ferruginous colour; these have no perfect parts of generation of either sex, but discover in their centre two, three or four papiliae or rudiments; these neutral flowers, with the whole pannicle, are truly permanent, remaining on the plant for years, until they dry and decay; the leaves which clothe the plants are very large, pinnatifid or palmated and serrated, or toothed, very much resembling the leaves of some of our Oaks; they sit opposite, supported by slender petioles and are of a fine, full green colour.
Oakleaf hydrangea is a fine garden shrub, one of the best used native shrubs in the nursery trade. Quite a few cultivars have been created to showcase dwarf qualities, different color forms and fancy flowers. The dwarf forms - such as ‘Pee Wee,’ ‘Sikes Dwarf,’ ‘Little Honey,’ ‘Ruby Slippers’ and ‘Munchkin’ - provide choices for the smaller garden since the species form grows to 8 feet tall and wide.

The flowers age to pink and remain on the plant in summer
The flowers are very popular with native insects. The fertile flowers are located inside the panicle (the showy flowers are sterile), but the pollinators (bees and beetles) know where to find them. The seeds are small and dry. Try collecting them and growing a few babies. You can also propagate the shrub from cuttings taken in the spring or by layering branches.

The four seasons of interest can be described as follows:

Spring – the soft gray-green leaves open before the flowers, oppositely arranged like two hands in prayer. The flowers bloom in very late spring, lush panicles of fertile and sterile flowers in creamy white.
Summer – strikingly large leaves offer handsome foliage all summer, accompanied by the still present flower panicles which have now transitioned to a dusky pink.
Fall – the leaves change to a variety of colors, even on the same plant. Some plants have bright leaf colors while others have muted shades of yellow, pink and russet. All are gorgeous. Flower panicles can still be present, now faded to the color of old lace.
Winter – while the leaves are late to fall, eventually they do, revealing stems of exfoliating bark and large leaf buds poised for the spring. Flower panicles may break off or may remain all winter.

Faded flower and muted fall color

Brilliant fall color
The one downside to this shrub is that deer are very fond of it (as they are of all hydrangeas). Put it in a protected area if you have deer. Then sit back and congratulate yourself on your excellent selection each and every time that you see it.

Peeling bark is evident on older branches

Bartram text courtesy of: Travels Through North & South Carolina, Georgia, East & West Florida, the Cherokee Country, the Extensive Territories of the Muscogulges, or Creek Confederacy, and the Country of the Chactaws; Containing An Account of the Soil and Natural Productions of Those Regions, Together with Observations on the Manners of the Indians. Embellished with Copper-Plates 
(spine) Bartram's Travels 

William Bartram
xxxiv, 522 p., ill.

Call number VC917 B29 (North Carolina Collection, University of North Carolina at Chapel Hill) 

Sunday, November 22, 2015

Deciduous Delights

Sweetgum leaf
People often seek out evergreen trees and shrubs for their landscape. The reasons are varied: for privacy reasons, because they like to have something green all year or perhaps as shelter for birds. 

All those reasons are good, but this time of year is the perfect time to realize that deciduous trees and shrubs are the ones that wow us in the fall. We should definitely include some of them in the landscape.
A sourwood (Oxydendrum arboreum) provides a red highlight
For weeks and weeks in the fall, deciduous woody plants stop producing green chlorophyll in their leaves and reveal amazing colors. As you may have learned, the exact color that the leaves turn has to do with the chemicals within them. Carotenes and xanthophyll pigments give us yellow, orange and brown colors while anthocyanin pigments give us reds and purples. Some of them even go through several color phases before they fall.

Landscapes with multiple colors catch your eye
The ideal fall combination is composed of plants that have fall color in all the categories: yellow, orange, red, purple and russet-brown. Include a few evergreens as well to provide the contrast. At minimum, you’ll want yellow, red and green. Now that fall is almost done, you might have realized that you were lacking in certain colors. I have previous posts that list some of our native choices for those colors: yellow and orange/red/purple. You can find some evergreen ideas here.

In addition to trees, there are some native shrubs with outstanding fall color: Viburnum, Fothergilla, native spireas (Spiraea), blueberry (Vaccinium) and huckleberry (Gaylussacia), and oakleaf hydrangea (Hydrangea quercifolia). Mix some of those in with your evergreen shrubs for a strong fall finish (plus they have great spring blooms).

Fothergilla, perhaps 'Mt. Airy'
Hydrangea quercifolia fall colors can be bright or muted as here

When the leaves are done falling, celebrate the free mulch and fertilizer that they provide while birds search for worms and tasty beetles beneath them. Deciduous woody plants are truly wonderful things to have in the landscape. If you didn’t have enough this year, I hope this post and the others linked here will give you some ideas for planting.

A deciduous forest offers so much to see

Sunday, November 15, 2015

The Last Hurrah

Canada goldenrod (Solidago altissima)
After over a week of rain, the ground is covered with wet and mostly gray-colored leaves. Half of our fall color-watching-season seems to have been washed away. 

I was thrilled to come upon this bright field this week, merrily sporting a knee-high sea of blooming Canada goldenrod (Solidago altissima).

Normally this species would have been much taller and the blooms would be finished by now. Someone must have mowed this field mid-summer, forcing the goldenrod to regroup its energies and put out all new growth. Mixed among the goldenrod are the bright red leaves of sumac (Rhus) at the same height.

As we finish out our fall and head into winter, this last burst of floral color is a happy sight. I hope that some of the monarch butterflies migrating southward might spot this field and stop by for some nectar. Someone did them a favor when they mowed this field for a change.

Sunday, November 8, 2015

Sumac – Roadside’s Rowdy Rhus

This time of year is when our native sumacs light up the roadsides with spectacular fall color. Any other time of year, these plants will not be noticed (or worse they will be removed as “weeds”). It’s a shame to see these plants so unappreciated. Let’s examine their qualities and perhaps we can convince a few people to let the suckering sumacs do their thing.

Smooth sumac (Rhus glabra)
I am speaking here of plants in the Rhus genus. This does not include plants with sumac as a common name such as poison sumac (which is Toxicodendron vernix) or stinking sumac (which is the non-native Ailanthus altissima). The sumacs that are native to Georgia include fragrant sumac (Rhus aromatica), winged sumac (Rhus copallinum), smooth sumac (Rhus glabra), staghorn sumac (Rhus typhina) and the uncommon Michaux’s sumac (Rhus michauxii).

Winged sumac (Rhus copallinum)
Of all these species, the two most likely ones you would encounter in Georgia are winged sumac and smooth sumac (easily distinguished from each other by the wings on the leaves of the first one). 

Both are large shrubs that spread by suckers and have striking fall color. The compound leaves have numerous leaflets. They also produce upright bundles of red fruits that birds adore, so without leaves they might be a bit hard to tell apart.   

Fragrant sumac (Rhus aromatica) on Stone Mountain

Fragrant sumac is a lowing growing shrub with only 3 leaflets and looks very similar to poison ivy. Like the other two species, the fruits are red although there are fewer of them. The red fruits help to distinguish it from poison ivy which has white berries. Like its Rhus cousins, fragrant sumac has great fall color too. In the winter, the presence of male catkins at the branch tips helps to identify it.

Beyond human aesthetics, sumac is beneficial to wildlife. During the growing season, at least 54 native moths and butterflies use it for a host plant for their eggs. The clusters of tiny flowers attract numerous pollinators. In the fall and winter, birds and small mammals eat the fruits.

Fruit of Rhus glabra
All 3 of these common Georgia species are tough, dependable plants. Their tolerance of average to poor soil makes them suitable for hard to grow areas and their suckering habits help to hold slopes and stabilize poor soils. 

While they might not be appropriate for a small garden except perhaps in a container, these adaptable shrubs can find a place in many larger landscapes. At the very least, let's hope they can continue to decorate our roadsides.

Smooth sumac on Lookout Mountain in North Georgia

Sunday, November 1, 2015

Growing Native Plants in Difficult Spots

People occasionally remark that they have trouble growing plants in their landscape because they have difficult conditions: pure clay, rocky soil, wet soil are the 3 most common reasons. This week’s blog offers some thoughts on that subject.
Aster that planted itself in a crack

First of all, native plants are well adapted to all the soils we have. Even nasty urban clay soils, stripped of the nutrient-rich top soils that they used to have, can support some of our tough-as-nails native plants. The solution is a matter of what you choose and how you plant it.

What you choose

Choosing potted plants from most nurseries and big box retailers is not the answer. These plants have two strikes against them: they are usually non-native and they have been grown in pots with soils that are optimal for growth (but not optimal for survival in your landscape). If you’re truly interested in having more success, pass on those.

Sourwood seedling in clay
Seeds are the way to grow plants in difficult spots, especially clay soils and rocky soils. Seeds put down a tiny root that grows and adapts to the conditions, even changing direction if needed. If you’ve ever seen a plant growing out of a crack, then you know how seeds can plant themselves and be successful.

Even so, the conditions must be right. You must do your research on what will thrive in your conditions: is the area sunny, shady, wet or dry?

Gather seeds when ripe

Once you have selected your target plants and obtained your seeds, do more research! Seeds have specific germination requirements: some want cold treatment before they will sprout, others need ample light (so don’t bury them too much) or warm soil temperatures … or even all of these things! It’s not complicated, so don’t be intimidated, but do pay attention.

Special note on seedlings: ask your friends if they get seedlings of plants that you want (and you know they have). They may offer you some of their extras.

Some of you won’t be willing to go the seed route and that is understandable. The next best choice is to select young plants that were grown by people that care about selling you good plants and having those plants actually live in your landscape. Smaller, younger plants have a better chance of getting settled into their new space if planted properly.

Special note when deciding: Plants that have a suckering/spreading habit will help you get more coverage, especially on hard-to-plant places like slopes.

How you plant it

There are so many ways to go wrong here. First, match the plant to the spot: sunny, shady, wet, dry. Next, dig the right size hole. The hole should not be any deeper than the plant’s pot (you don’t want it to sink later) and no wider than twice the pot's width. Gently tease apart any roots that are crowded.

Do not add amendments to the planting hole and definitely don’t replace the native soil with new soil. The plant needs to get used to this dirt. Some people even rinse off some of the dirt from the pot, but I don’t like to disturb the roots too much. Press the dirt into the hole afterwards to ensure good root-to-soil contact and remove air pockets.


How you treat the plant afterwards is important too. Native plants are tough, but they need water until they get established. Water the plant as needed and use organic mulch to help retain water around it (chopped leaves, pine straw, undyed hardwood mulch) and to provide nutrients as the mulch breaks down. Keep the mulch far enough away from the stem to avoid smothering it, but close enough to keep the ground from drying out.

Special note: Group plants with similar water needs together, just like nature would do. That way any watering you need to do can be done together.

I hope these ideas might have helped you to see a path towards using more native plants in what might seem to be difficult areas. Nature always finds a way and you can too.