Latin for Gardeners: July and August 2020

July and August Native Maryland Plants

Hypericum densiflorum Pursh.
(hy-PER-ee-kum den-see-FLOR-um)
Common Name: Dense St. John’s Wort

Hypericum prolificum L.
(hy-PER-ee-kum pro-LIF-ih-kum)
Common Name: Shrubby St. John’s Wort

This month I want to share with you two plants that are commonly confused with one another: Hypericum densiflorum and Hypericum prolificum.  By discussing them side-by side I hope to show you how to differentiate them if you ever see them in your work or travels. These Hypericum spp. bloom all summer long, are native to the Mid-Atlantic states and are very low maintenance. Four years ago I planted a single specimen of each so I could learn to differentiate them; I sited them near each other along my driveway where they get full unobstructed sun and no maintenance.  They have been blooming profusely since early June and because of their proximity to one another are easily distinguished. 

At first glance you notice that both the flowers and the leaves of H. densiflorum are noticeably smaller than those of H. prolificum and there are more flowers to each inflorescence.  True to its name, the habit and flowering of H. densiflorum is a much denser shrub with flowers that are tightly clustered. H. prolificum has a more open habit with slightly larger flowers that grow in less crowded clusters on a stem. The stems of each plant are worth a closer look:  H. densiflorum is smooth and copper colored while mature H. prolificum appears woody and exfoliates in winter, exposing a light brown to orange bark.

Each plants’ flower has five petals and countless long yellow stamen that give the flower a frilly look -they can even obscure the petals. These flowers contain pollen but no nectar so bees are common visitors, butterflies are rare.  Interestingly, both shrubs are a host plant for the gray hairstreak butterfly (Strymon melinus) and several moths.  These Hypericum species leaf out early and are teeming with bees as soon as they get a single bloom.  They are often planted as erosion control plants; they have good drought tolerance and can easily be pruned to contain their height, if desired.

NOTE: Foliage contains a phototoxic chemical which deters deer and other herbivores.  Rutgers rates this plant a B: Seldom Severely Damaged by deer: https://njaes.rutgers.edu/deer-resistant-plants/

~ Alison Milligan – Mstr. Gardener/Mstr. Naturalist/Mstr. Watershed Steward

Chesapeake Bay Landscape Professional (CBLP)

aligmilligan@gmail.com

Latin for Gardeners: June 2020

June’s Native Maryland Plant
Carex plantaginea Lam.
(KARE-eks plan-taj-in-EE-ah)
Common Name: Seersucker Sedge or Plantain-leaf Sedge

The Covid-19 pandemic has meant that I, like many of you, have been spending most of my time at home, keeping safe and reducing my risk of getting the coronavirus. For me, being at home has meant even more time in the garden, intently observing nature and the emergence of spring while also having the opportunity to look at my plants with a more critical eye. I have been using this time to determine which plants are best at suppressing weeds and reducing maintenance to save myself even more time once things get back to normal.

One plant I’ve grown to admire for its ability to compete with invasives (e.g. periwinkle, Japanese stiltgrass) is Carex plantaginea. This rather ornamental sedge that I planted 3 years ago in a large swath of moist shade under high canopy trees has shown itself to be a star. Because it emerges in early spring, it is effective at suppressing weeds while creating an attractive groundcover along the way - its wide, puckered leaves and showy inflorescence add unexpected visual interest. The common name, seersucker sedge, refers to its crinkled leaves which resemble the very breathable summer fabric known as seersucker – traditionally worn in the South between Memorial Day and Labor Day.

If you prefer planting to pulling weeds in your garden – give Carex plantaginea a try. You may find it gives you just a bit more time on your hands – not on your knees!

NOTE: There are over 1500 species in the genus Carex.  Other members of the Cyperaceae family are also called sedges, but those of the genus Carex are called "true" sedges. The study of Carex is known as caricology.

~ Alison Milligan – Mstr. Gardener/Mstr. Naturalist/Mstr. Watershed Steward

Chesapeake Bay Landscape Professional (CBLP)

aligmilligan@gmail.com

Latin for Gardeners: May 2020

May’s Native Maryland Plant
Caltha palustris L.
(KAL-thuh puh-LUSS-triss)
Common Name: Marsh Marigold

Like most Marylanders I have ‘forever wet’ areas in my yard that consist of heavy clay or compacted soil.  It can be difficult to grow your standard moisture-loving native plant in these poor drainage areas, and don’t even think about growing grass there - you’ll just have a mucky mess that you can’t mow.  After losing my shoe in the ‘muck’ two years ago I decided to tackle the site once and for all. I knew there had to be some plants that could grow in these conditions, but which ones?

I instinctively turned to Maryland’s list of native wetland plants.  Caltha palustris stood out to me immediately; it’s an obligate wetland (OBL)¹ plant and its specific epithet, palustris refers to its preferred habitat: "swampy, marshy, or forested wetlands" e.g. my backyard. Its low-growing stature and early bloom period made it especially attractive.  I eagerly sought it out and planted it (using plenty of compost) in multiple areas before deciding if it was ‘the one’. After two years I was sold.  Caltha palustris is thriving in my yard and attracts a diversity of pollinators in early spring, a time of year when they are searching for the few blooming plants that can sustain them.

Marsh marigold has hollow stems; its flower has numerous stamen and 5 to 9 petal-like sepals but no petals. In late May the follicle² will split and throw seed. As is the case with many wetland plants, the seed is buoyant and can easily float to a nearby location where its high germination rate all but guarantees it will propagate. If you are struggling with similar ‘muck’ in your yard, why not give marsh marigold a try?  It may be ‘the one’ for you too!

¹ OBL: Obligate Wetland - Almost always occur in wetlands

² Follicle: the fruit that matures into a seedpod

~ Alison Milligan – Mstr. Gardener/Mstr. Naturalist/Mstr. Watershed Steward

Chesapeake Bay Landscape Professional (CBLP)

aligmilligan@gmail.com

Latin for Gardeners: April 2020

April’s Native Maryland Plant 
Viburnum acerifolium L.
(vih-BUR-num a-ser-ih-FOH-lee-um)
Common Name: Maple-Leaved Arrowwood

This month marks the beginning of my fourth year writing Latin for Gardeners.  Looking back at the list of plants I’ve discussed I was surprised that I had yet to mention any Viburnum species. This specific one, V. acerifolium, is one of my favorite shrubs, for multiple reasons.  It has great fall color, attracts a diversity of pollinators, is a host plant for the Spring Azure butterfly and its dense branches are where I often see birds foraging or nesting.  They also enjoy the black berries that appear in early fall! 

V. acerifolium prefers some level of shade, it will not endure boggy soil or over-watering but will tolerate drier conditions. It occurs naturally in beech-maple forests, thriving in rich deciduous woods, often amongst oak where it benefits from the acidic leaf litter. It’s also tolerant of black walnut toxicity.

Although I have many Viburnum spp. in my yard, I have yet to see the destructive Viburnum leaf beetle. I inspect my plants in spring before they leaf out and if necessary I’ll aggressively prune or treat them. Providing the best possible growing environment allows for a healthier plant which is always the best defense against any plant-eating insect or disease.

V. acerifolium is not found at most garden centers so if you find one and choose to buy it, (and I hope you do), I recommend you purchase the biggest plant you can find!

*Corymb: A flower cluster whose lower stalks are proportionally longer so that the flowers form a flat or slightly convex head.

NOTE: Spring azure photo used with Mary Anne Borge’s permission: https://the-natural-web.org/

~ Alison Milligan – Mstr. Gardener/Mstr. Naturalist/Mstr. Watershed Steward

Chesapeake Bay Landscape Professional (CBLP)

aligmilligan@gmail.com