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Looking around the farm fields of Southern Lancaster County in late July there are three main things happening. The corn is in tassel, tobacco is starting to flower and I finally have fresh tomatoes for my BLTs.

The corn tassel is the male flower of the plant. Those yellow turkey-feet looking things contain over 10 million pollen grains. Each kernel of corn requires pollination by a separate pollen grain. While most plants require an insect or bird to complete their pollination, grasses like corn are wind pollinated. Tassels are high, at the top of the plant, so the pollen grains can fall onto the ears (female flowers) below, or be carried on the wind to nearby ears. A tassel releases its pollen mostly in the morning over several days. An entire field of corn will shed all its pollen in about two weeks. When temperatures are above 85, pollen shed is more rapid. For those allergy sufferers like me, the last few weeks have been rough.

Last week the tobacco started coming into flower too. Unlike corn, where the fruits are very important, tobacco is grown for the leaves. Tobacco is an annual plant, meaning it completes its life cycle in one season. The seeds germinate in the spring, the leaves grow though June and early July and the then it blooms to make more seed for the future. However farmers don’t want to make seed, they want many large leaves. To circumvent the plants natural life cycle, farmers will be out shortly removing all those stalks of large white flowers. This will keep the plants energy into making more leaves.

Looking at our own gardens tomatoes are coming in now. We’ve gotten several questions recently regarding blossom end rot. Despite its rather confusing name, it is not a fungus at all, but a nutrient deficiency. If you have brown spots at the bottom of your ripening fruit, your plants need more calcium. At the beginning of the season mix fast-acting lime into the top foot of your garden soil to both add calcium and raise soil pH to make calcium more available to the plant.

Late in the season when fruit is already developing, you can spray a calcium solution made to combat blossom end rot directly on your plants 2-3 times a week. This is a stop-gap measure at best. If you are struggling with blossom end rot now, remember to amend you soil next spring before planting tomatoes, peppers or eggplant. Pick off fruits already showing brown spots.

Keep tomato plants moist; drought stress exacerbates blossom end rot. This hot dry weather is not helping.

Looking forward on the garden calendar, now is the time to plant fall vegetables. Broccoli, cauliflower, Brussels sprouts and cabbage should go in now so they have enough time to form nice large heads. Lettuce, kale and spinach can go in anytime from now through September.

Driving around Lancaster County farm fields look robust and wildflowers are blooming, but I wouldn’t say “no” to some rain.

We are very fortunate to live in an area populated with many beautiful and unique public gardens. Last week we visited one of my favorites. Chanticleer Garden in Wayne, PA features 35 acres open to the public from April through October.

The estate was built by Rosengarten family in the early 20th century as a “country retreat” from their Philadelphia home and pharmaceutical business. Like the DuPonts who also made their money in chemicals, they left a tremendous public legacy, turning their home into a premier garden and opening it to the public upon their death.

Still relatively new, the garden opened for visitors in 1993. 14 gardeners and groundskeepers manage the estate. Chanticleer has a whimsical feel and doesn’t take itself too seriously. The gardens are comprised of several areas ranging from tropical plants and seasonal potted displays around the house, vegetable and cut flower gardens, a folly garden built around a stone “ruin” with several water features, koi ponds with water plants and an Asian-inspired woods which is a great retreat on a 95 degree day in July. Sprinkled throughout the garden are art pieces primarily crafted by the gardeners including an intricately carved bridge, painted Aderondack chairs, a small shed painted with a woodland mural which my kids LOVE, and other sculptures.

Our staff takes a field trip every summer to visit local gardens, and we have had the pleasure to visit Scott Arboretum, Longwood, Winterthur, Mt. Cuba, Ladew, the Tyler Arboretum and Goodstay. Many of these places in addition to lovely grounds, also have an educational component. They offer classes on plant identification, photography, landscape design, and native plants. This combination of quality botanical gardens and education leads to people interested in and aware of beautiful landscapes. These consumers demand the plants they see used, which in turns creates a need for wonderful quality garden centers and greenhouses. There are very few places in the country where you can drive around and see the quality of landscape plantings in regular neighborhoods as in Southeastern PA, Delaware and Northern Maryland.

So I offer my thanks to the DuPonts, the Rosengartens, the Copelands and the Wheelrights and those like them who made their fortunes in this great country and used their resources to build something beautiful that will live on and inspire others long after they were gone.

Hydrangeas are among the most beloved, commonly grown and often cursed shrubs in our landscape. Last week we tackled two of the four types; white snowball hydrangeas bloom in June on new wood and the blue or pink mophead hydrangeas that regularly fail to bloom after a cold winter. This week, panicle and oakleaf hydrandgeas get their chance to shine.

Panicle hydrangeas or Peegees (short ofHydrangea paniculata‘Grandiflora’), refer to their cone-shaped panicle flowers. The blossoms emerge in July a greenish-white and fade through pink to beige. 20 years ago before very much breeding work was done on them, they were very popular and overplanted. 15-20 feet tall and 10-20 feet wide, they were difficult to fit into most landscapes. Homeowners had to aggressively prune them or rip them out after several years. They do bloom on new growth, so can be cut back hard in the spring without sacrificing flowers and do not suffer from winter kill like the blue mopheads. These hydrangeas perform best in t least 5-6 hours of sun.

Over the last 10 years, breeders have focused on shrinking them to fit smaller landscapes. One of the most popular cultivars is ‘Limelight’ which reaches 6-8 feet. Dwarf cultivars like ‘Little Lime’ and ‘Bobo’ have shrunk even further, looking more at home in the perennial border than as a substantial shrub. Other breeding efforts have manipulated the flower color to a deeper pink. Mixtures of fertile and sterile flowers give a lacey appearance to some cultivars as well.

The fourth type of hydrangea commonly grown is another native, the oakleaf hydrangea (Hydrangea quercifolia).These bloom on old wood in late June-August. By the fall the creamy white flowers have faded to beige. These shrubs have a coarser texture due to the large foliage size.

Though gaining in popularity, they still are underutilized in the landscape. It is one of dad’s favorite shrubs due to three seasons of interest. Mature plants have exfoliating bark; meaning the stems look like peeling cinnamon sticks over the winter. This sounds weird, but actually looks really interesting. Attractive blooms in the summer and deep purple-red fall color round out a solid 10 months when the plant is nice to look at.

Several sizes are available to fit most landscape needs. An old favorite ‘Snow Queen’ is advertised to reach 7-10 feet. It softens a lattice wall on the farm and after about 20 years of minimal pruning is at least that big. Dwarf varieties like ‘Munchkin’ top out at 3-4ft. Older small selections tended to sprawl, but ‘Munchkin’, introduced by the US National Arboretum, held its shape well over an extensive trialing period.

Another National Arboretum introduction is ‘Ruby Slippers’. While all oakleaf hydrangea flowers emerge white and fade to pinkish beige, this selection ends up the darkest reddish pink of the bunch. There is a chartreuse foliaged selection called ‘Little Honey’ which is interesting to lighten a shady corner, but it flowers very sporadically, completely missing the point of hydrangeas in my humble opinion.

Oakleaf hydrangeas are another type that blooms on old wood, so if you need to prune for shape, do so immediately after the bloom to not lose next season’s flowers. The flip side is, the flower buds are extremely cold hardy, unlike the blue/pink mopheads, so you rarely lose flowers from winter kill of the buds.

Culturally both panicle and oakleaf hydrangeas do well in full sun- partial shade. Oakleafs will tolerate a bit more shade. They are not picky about soil, but avoid waterlogged situations.

There is also a species of vining hydrangea, as well as a false hydrangea vine. If you are looking for a woody, beefy flowering vine they are worth investigating.

Hopefully this brief tutorial clears up some questions. I have several hydrangeas planted at the farm, some I love, and some I tolerate. But you can find one to meet most landscape challenges.

Photo Hydrangea quercifolia 'Ruby Slippers' courtesy of the US National Arboretum.

These columns are mostly fueled by comments or questions by our customers. Given the queries of the last few days, hydrangeas are a subject that needs addressing.

There are four main species of hydrangeas commonly grown. Two are US natives, two are from Asia. Two bloom on new wood, two bloom on last summer’s growth. One comes in blue or pink, the other three in shades of greenish-whitish-beige. One has nice fall color- the other three are non-descript. One can easily be trained into a tree form, the other three are rather coarse-textured shrubs for the back of the perennial border, foundation planting or shrub border.

Alphabetically and earliest to bloom are theHydrangea arborescens. Native from New York to Florida, it performs well in a broad range of habitats. It is commonly called Smooth Hydrangea, though I don’t really know why, I always called them snowball bushes. These are the best hydrangea for shade, even blooming well in deep shade. It is also the least woody of the bunch. It can be pruned to the ground in late winter, and will still bloom by mid-June. The large round flowers emerge greenish-white, then fade to tan. At this point if you have a lot of spare time, they can be cut back to the ground, the flowers dried for everlasting arrangements and with luck, you’ll get a second flush of flowers in the fall. Popular cultivars include ‘Anabelle’ and the insanely large-flowered Proven Winners offering Incrediball™.

Next to bloom are Hydrangea macrophylla.The large-leaf hydrangeas are the plants most people think of when you say “hydrangea”. They are native to Japan, which has a more maritime climate. This gives an explanation why they don’t always bloom well for us here. Traditionally, flower buds were formed in the late summer of the previous year. A frigid winter, or late cold snap kills the buds, robbing us of a summer’s worth of flowers. I have one in my yard, that I haven’t seen bloom in several years. Plant breeders put their thinking caps on and about 10 years ago introduced reblooming hydrangeas. Endless Summer ™ was the first, followed by Let’s Dance™ hybrids and Forever and Ever™ selections. Regardless of the cultivar, the idea is the same. Even if the old buds are wiped out over the winter, the new season’s growth will still flower. Win-win.

The flower color depends on the pH of the soil; specifically the availability of aluminum ions. Flowers are blue at a low pH, pink at higher pH. Our soils tend to yield pink ones. Down at the shore, they are more often blue. To get blue, mix aluminum sulfate, agricultural sulfur or peat moss into the soil to lower the pH. Be careful not to add too much at once, lest you burn the foliage. I speak from experience. It is also better done in the early spring, or at planting, not when they are already blooming.

Their flowers are also either sterile (with large petals) or fertile (almost no petals). The large mop heads are primarily clusters of sterile flowers. The lace cap effect is the combination of sterile and fertile flowers. I’ve never seen them reseed- so this is a bit of a moot point- mostly just aesthetics.

Best time to prune them is after they are done blooming to shape. However they shouldn’t need much. They perform best in morning sun with a little protection from afternoon rays- otherwise they can look a bit droopy.

Well, I’m about at the end of my space and have two more kinds to discuss. Look for part two next week.

Above right, Hydrangea arborescens Incrediball (TM).  Above left Hydrangea macrophylla Endless Summer (TM).

Agastache is at the top of my list for hummingbird and pollinator friendly plants.

Known by several names, hummingbird mint or hyssop, is a not surprisingly, a member of the mint family. Mints are characterized by square stems, strongly fragrant foliage, and tubular clustered flowers. Never fear, not all are spreading; most agastache won’t overrun your flower beds.

There are several species commonly grown, some are hardier than others. In general, I would classify agastaches as short-lived perennials. Often they reseed a bit, but I would expect to replant them every 4 -6 years. In general, the blue-flowering ones are hardier than the red or orange flowering ones.

One of my favorites isAgastache rupestris,commonly called licorice mint or sunset hyssop. It has thin gray-green foliage, and smoky orange flowers. They are nectar heavy and bloom for a long period from summer through early fall. The foliage smells strongly of anise, hence one of its common names . It is native to Arizona and New Mexico and as you would expect, prefers dry soil in a sunny area. They are easy to love to death with overwatering.

Most of the blue-flowering ones areAgastache foeniculum hybrids. Blue hyssop has wider heart-shaped or triangular leaves and reaches 2-4 feet. This species is native over most of the upper US and is found in prairies and dry upland forests, including Pennsylvania. They are also great treats for pollinators and hummingbirds, but are better suited for our wetter Eastern gardens thanA. rupestris.

There is a pretty gold-foliaged selection named ‘Golden Jubilee’ topped with purple flowers. It has resided in my friend’s shady garden for years, seeding gently around and filling in a six-foot area. Despite growing best in sun, this selection really brightens up a shady corner of his garden.

Other hybrids come in pink, oranges and reds. These generally do not reseed, but are full of nectar for our pollinator friends.

To care for agastaches, water them sparingly to get established, after that, leave the water hose alone. Trim them back to shape, and deadhead as needed. The lean back and enjoy the wildlife that thanks you for your efforts.