Set on twenty-five acres adjacent to Rock Creek Park, Hillwood’s gardens feature a diverse and fascinating array of trees, shrubs and herbaceous plants, offering something to see in every season. 

Plants to note in the gardens:

• This is the last weekend to see this year’s summer seasonal display which is comprised of more than ten thousand warm season annuals and tropical plants. The vinca (Catharanthus roseus ‘Valiant Punch’ and ‘Valiant White’) along Friendship Walk are looking exceptionally nice. Vinca tend to like it hot and dry and are plagued by disease during rainy weather. The ‘Valiant’ series is quite disease resistant and made it through our wet June and July unscathed.
• It is goldenrod (Solidago spp.) season and bright yellow flowers are popping out throughout the gardens. Many believe them to be the cause of seasonal allergies, but really it is the wind-born pollen of ragweed that is the culprit. We have quite a few different goldenrods throughout the property. A beautiful stand of Solidago rugosa ‘Fireworks’ can be found in the cutting garden. The delicate flowers provide late season nectar for bees and butterflies and later seeds for birds.
• The autumn crocuses (Colchicum spp.) are in bloom outside of the French parterre. These fall blooming bulbs are always a surprise as they develop flowers without any leaves. Though the purple flowers are reminiscent of spring crocus, colchicum are more closely related to lilies with six yellow stamens in the center. Spring crocuses have three. The foliage will appear next spring and die back in the summer. This particular grouping is attributed to when Marjorie Post was in residence.

Highlights in the greenhouse:

• The large Dendrochilum magnum does not look like a traditional orchid. Two straight rows of tiny yellow orchid flowers line the flower stalk. The stalks turn downward, creating an elegant weeping effect. The plants can be quite prolific and flowers can last for several weeks. Their sweet fragrance with a hint of spice can be quite noticeable upon entering the orchid house. Dendrochilum magnum is the largest of the dendrochilum species and lives at high elevations in the Philippines.
• Towering overhead, you may get a glimpse of an upside-down orchid (Stanhopea Ronsard). These interesting plants produce pendulous yellow flowers with maroon spots that push out of the bottom of their pots! Special growing baskets allow space for the flower stem development. These fragrant flowers only last a few days, but multiple flower spikes can form over the summer. This is a hybrid of two species found from Mexico down to South America. See if you can catch one in bloom.
• There are some lovely vanda orchids in bloom. The large flowers of Vanda Pachara Delight 'Pachara' are some of the best true purple flowers in our collection. Vandas are grown without a true pot and can be distinguished by their long, hanging root systems. The plant has a monopodial growth habit meaning that it grows upright from a single stem. The flower spike emerges from the axil of the leaf, referring to the point where the leaf meets the stem. The vanda orchid in the national flower of Singapore.