Summer Annuals
Begonia – Begonia
Zone: 8-11
Light Requirements: Full sun to Full Shade
Soil Preference: Average well drained soils
Pests/disease: Mealy bugs, rot
Attributes: Begonias are succulent herbs from the tropics that are utilized in the summer garden for their many attributes. Over a thousand species of begonia exist, breaking up into three main categories, fibrous rooted (e.g. wax begonias), rhizomatous (e.g. rex begonias) and tuberous rooted (tuberhybrida varieties). Begonia come in a variety of sizes from as small as 6” to as large as 3’. While begonia have varying sun tolerances, all enjoy the filtered light of a shady spot bringing to it flower color or leaf texture (or both) depending on the plant. Begonia boast few diseases so long as watering is closely monitored. Begonias are also virtually deer and rabbit proof.
Our Experience: We use a ton of begonia on Great Hill in our outdoor as well as indoor garden spaces. They are a clutch plant in a shade garden or in a shady urn, shining where other plants languish. We love larger hybrids for big blocks of color in our annual and perennial display beds and we have a number of begonia brightening up our indoor spaces.
Bush violet- Browallia
Zone: 9-11
Light Requirements: Part shade
Soil Preference: Moist well drained soils
Pests/disease: None serious
Attributes: Browallia is a compact annual with tubular purple blue flowers and woody base growing 12-16” and blooming from summer to fall. While it will tolerate morning sun, it does best in part to full shade during the afternoon hours in the summer. Does not require deadheading.
Our Experience: We absolutely love browallia for shady areas on the hill. Couple its shade tolerance with the rare purple blue bloom color and it really stands out, bringing interest to areas that might have only been planted with foliar color in the past. Could also be impactful for pops of summer color in woodland locations and shady containers.
False Heather – Cuphea
Zone: 8-11
Light Requirements: Full sun
Soil Preference: Average well drained soils
Pests/disease: Root rot, leaf spot, whiteflies and aphids
Attributes: Cuphea is a genus of annuals with over 250 different species to its name. For summer color in our zone, cuphea hyssopifolia and cuphea ignea are the more popular varieties sold by local growers and garden centers. These cuphea love high quality soils with good drainage and regular water. They prefer to be planted in protected areas. Flower types vary depending on variety. For example, Cuphea ignea has long tubular flowers in red shades and cuphea hyssopifolia has radial flowers that come most commonly in pinks and purples. Cuphea is a clump forming semi woody annual that grows anywhere from 12 to 24” in height and width and is used in urns as well as planted in beds.
Our Experience: We love cuphea ignea (firecracker plant) on Great Hill. Its long, colorful stems bring a lot of movement to our garden beds and it gets absolutely mauled all season by both hummingbirds and butterflies. If the plants start to get to leggy, we trim the top third to create a shrubbier form.
Sunpatiens- Impatiens hawkeri Sunpatien Series
Zone: 10-12
Light Requirements: Full Sun to Part Shade
Soil Preference: Medium moisture, well drained soils
Pests/disease: None serious.
Attributes: Sunpatiens are a New Guinea impatiens hybrid that can tolerate full sun, high heat and humidity, and are much more resistant to rot, powdery mildew and other fungal diseases than the well known NG impatens standard. Sunpatiens are also a more robust plant having a bushier habit and growing much taller, to 4.’ Sunpatiens come in many colors (orange, pink, white, red etc.) and habit forms (compact, mounding, spreading, vigorous etc.). Bloom from early summer to late fall.
Our Experience: We use this annual heavily on the hill. It has thrived in both full sun and nearly full shade conditions, is left alone by deer and rabbit and comes in a range of heights and sizes. Add to that impressive list that sunpatiens bloom for months, are virtually maintenance free other than watering and feeding, and are highly disease resistant. Sunpatiens can be used in containers, but make a real impact as a bedding plant, providing long swaths of color throughout summer and fall.
Lantana- Lantana camara
Zone: 9-11
Light Requirements: Full Sun
Soil Preference: Medium moisture well drained soils
Pests/disease: None serious
Attributes: Lantana is a summer flowering annual with tiny lobed flowers that bloom in clusters from summer to fall. Lantana has a woody base, grows to 3’ and comes in a variety of colors that are often mixed in the same cluster. Leaves are aromatic.
Our Experience: We use lantana both in beds and containers for long lasting and impactful summer color. While labor intensive, it does benefit the plant to regularly deadhead spent blooms and remove seed heads. Great plant for attracting butterflies!
Egyptian star flower- Pentas
Zone: 10-11
Light Requirements: Full Sun
Soil Preference: Medium moisture well drained soils
Pests/disease: None serious
Attributes: Pentas is a summer annual with clusters of star shaped flowers (often red, pink, lavender or white) that grow 1-2’ and bloom until first frost in the fall. Pentas are relatively low maintenance, infrequently requiring deadheading.
Our Experience: Pentas is a favorite summer bloomer for large bedding areas on great hill. It’s left alone by critters, is not prone to disease, and persists with water, feeding and little deadheading. Its habit is both clustering and sprawling, so it takes up space quickly and it blooms robustly.
Coleus- Plectranthus or Solenostemon
Zone: 10-11
Light Requirements: Sun to Full Shade depending on variety
Soil Preference: Medium moisture well drained soils
Pests/disease: None serious
Attributes: Coleus, while flowering, is often utilized for its foliar interest in shady garden locations (though some varieties can tolerate full sun conditions). It can grow to 3’ and comes in a variety of forms and a multitude of multi-colors. Blue to white nettle like flowers bloom in early fall.
Our Experience: Coleus is a foliar standard for annual beds and containers in shaded locations. The range of colors available make it possible to pair with almost any color combination. While it does bloom, the flowers are not showy. We pinch back buds or cut off blooms when they appear as their maturity results in foliar decline, and visually detracts from the foliage, which is the real aesthetic component of this plant.
Fan Flower- Scaevola
Zone: 10-11
Light Requirements: Full sun to Part Shade
Soil Preference: Average well drained soils
Pests/disease: None serious
Attributes: Scaevola is a popular sprawling annual that thrives in hot, humid environments and is often utilized in hanging baskets and urns. Each plant can grow to over 12” in height with a spread of 24”. Commonly called ‘fan flower” due to its prolific fan shaped flowers that bloom in shades of blue, white and purple from summer until frost.
Our Experience: Scaevola is a super performer on Great Hill. We use this annual in urns as well as annual display beds. We’ve found that scaevola performs best in the hot, dry areas that often kill other less tolerant annuals. We utilize it in beds that abut pavement or areas with sandy and or poor soils. Scaevola care is easy. To prolong blooms, we deadhead to a bud roughly once monthly during the growing season and feed with a bloom boosting fertilizer every couple of weeks.
Zinnia- Zinnia
Zone: 10-12
Light Requirements: Full sun
Soil Preference: Medium moisture well drained soils
Pests/disease: Mildew, leaf spot and blight depending on species
Attributes: Zinnia is a huge genus of species, all with many cultivars. Commonly grown species, used as annual plants in our zone, are zinnia elegans, zinnia angustifolia and the hybrid, zinnia elegans x angustifolia (the profusion series). Zinnias daisy like flowers come in a number of colors, grow to 3,’ and bloom profusely for long periods of time. Zinnias are also widely utilized for cut flower arrangements.
Our Experience: As we have had many fungal disease issues with our annual plants on great hill, we tend not to plant zinnia elegans, which seems plagued by fungal disease no matter the summer conditions. Whichever species you are using, planting with adequate space to allow for air circulation and water absorbtion is very important when working with this plant. Requires frequent deadheading.