Blooming Blurbs: Part 5 by Grace Willis

 There's always something new blooming in The Gardens!

Sacred Datura (Datura wrightii)

These stunning white flowers can be found in our Fragrance and Entrance Gardens. You may notice that these blooms resemble those from the angel’s trumpet tree from Blooming Blurbs Part Two. This is because both the Datura and Brugmansia genera come from the Solanaceae family. In fact, all members of the Brugmansia genus were placed under the Datura genus until 1973, when three key differences were identified. Brugmansia flowers tend to be pendulous (hang down), be white, peach, or yellow and have smooth fruits. Datura flowers, on the other hand, are upright, white, or soft purple, and their fruits are spiky and rough to the touch. Both are poisonous, so look but don’t touch. This plant can bloom all the way from April to October when given the proper care and conditions. 

Care information: Datura wrightii is considered to be a perennial in zones 5-11 and an annual in other zones. In order for it to be an annual in zones 5 and 6 however, it needs to be planted in a warm spot with good drainage. This plant is reseeding and will typically come back each year if spent flowers are left to seed, regardless of its annual/perennial designation. It prefers full sun and a steady amount of moisture in well-drained soil. For our climate, this typically means watering once or twice a week. As new plants start to come up in the spring, it is a good idea to add nitrogen-rich plant food. After the plant has reached about two feet tall, a phosphorus-rich fertilizer can be added as well to promote more abundant blooms. This plant can grow to be three feet tall and four to five feet wide, so it is important to plant it in an area with space for spreading out, especially in the case of multiple reseedings. Cutbacks are typically not needed other than for desired aesthetic reasons or removing spent blooms before fruiting. Its fruits are, as previously stated, round and spiky so they can actually add to aesthetics depending on personal preferences.  

For more information, reference our Gardens Explorer 

 
Blue Mist Spirea (Caryopteris x clandonensis ‘Dark Knight’)

These bursting blue blooms can be found in our Pollinator Garden in the Garden of Eatin’ and our Flowering Tree and Shrub Grove. This deciduous shrub came around by the accidental cross of C. incana and C. mongholica. This cross was found to be favorable for its profuse, deep blue-purple blooms and, therefore, found its way into the horticultural world. As with many other members of the mint family (Lamiaceae), it has a strong, sweet fragrance. It also has an abundance of nectar that commonly attracts bees, butterflies, and hummingbirds. Due to its coloration, bees are its most frequent pollinators since their eyes can pick up on blues and purples. These blooms typically start in mid-July and cease around September. Due to its late bloom time, it can be a good addition to gardens with mostly early-summer blooms to add some color during the later months. 

Care information: The blue mist spirea prefers full sun and is hardy in zones 5 through 9. The ideal soil for this plant is well-drained and either neutral or alkaline. If the soil isn’t well-drained, this can lead to standing water, which may cause root rot in this plant. Watering should occur twice a week, at least for the first year after planting, to help establish a strong root system. After the first year, Caryopteris x clandonensis ‘Dark Knight’ can tolerate watering once a week. In the spring, a balanced slow-release fertilizer can be added to the base of the plant to promote growth and more blooms. At its peak, one plant can get to be four feet wide and tall, so it is important to space them out when planting. This is especially important if you aren’t planning on cutting back the plant for shape/aesthetics each year. 

For more information, reference our Gardens Explorer 

Butterfly Weed (Asclepias tuberosa) 

These orange blooms can be found in many of our gardens, including our Sustainable Backyard, Prairie Garden, and Potager Garden. It is native to much of the United States, including Colorado, and can often be found in more open areas such as meadows, prairies, sparse forests, and along roads. Its narrow, dark green leaves provide a contrasting background that makes the various shades of orange on each bloom stand out. These blooms are a part of the milkweed family (Apocynaceae) and therefore exhibit a unique structure. Each bloom contains a crown/corona, which is the upper, protruding part of the flower, and 5 petals and sepals, which are spread out beneath the crown. As its name and family suggest, the butterfly weed primarily attracts butterflies as pollinators and is a host plant for monarch, gray hairstreak, and queen butterflies. This plant can take up to three years to actually produce blooms, but blooms will get more dense in number each year after maturity is reached. These blooms last a while, usually from May to September, which is decently longer than average. 

Care information: Asclepias tuberosa does best in zones 3-9. It should be planted in well-drained soils with full sun exposure. There are purchasable forms that are adapted to soils with poorer drainage, such as un-bermed clays, but a majority of the forms sold will need soils with good drainage. These seeds don’t require any treatment before being planted, so they can just be planted from seed in the desired area. They should be watered twice a week during the growing season but can tolerate once a week after they’ve been established for a couple of years. Fertilizing is typically not necessary for this plant. The large, pointed seed pods will turn brown towards the end of the season and burst open, causing seeds to be dispersed nearby. If you don’t want butterfly weed to spread across your garden, it is a good idea to remove each pod when it’s still green and fresh. 

For more information, reference our Gardens Explorer 

Colorado Four O’clock (Mirabilis multiflora) 

These gorgeous purple flowers can be found in our Moon, Rock, and Foothills Gardens. As hinted by its nomenclature, these blooms don‘t open until around 4 o‘clock in the afternoon. If it is a cloudy day, they will typically open sooner. This is partially because they prefer the cooler temperatures of the afternoon but mostly because of their pollinators. These flowers don‘t rely on daytime pollinators such as bees and butterflies but rather more nocturnal pollinators like moths. They are open throughout the night and then close again when the sun rises, and their pollinators go to sleep. These flowers are native to Colorado and typically bloom all the way from April to September, which, similar to butterfly weed, is a very long blooming season. 

Care information: Though its blooms don’t care for the sun, Mirabilis multiflora prefers areas with full sun and well-drained soils. Rocky and sandy soils are technically best for this plant, but it will do just fine in almost any texture. It is hardy in zones 4 through 8. During its first growing season after being planted, it should be watered at least once a week. However, even in our climate, this is a highly drought-tolerant plant and doesn’t need to be watered even weekly due to its large, fleshy taproot. During the winter, it will die back to the ground and regrow from its roots, so cutting it back before winter can help avoid as much spring cleanup. Just one plant can spread to be 5 or 6 feet in diameter, so make sure to account for this when planting near other plants.  

For more information, reference our Gardens Explorer 

 
Showy Sedum (Hylotelephium Sedum ‘Thunderhead’) 

These bright pink flowers and succulent foliage can be found on the western side of our Welcome Garden. Each bunch of flowers features hundreds of star-shaped, rose-colored flowers. These are held up above gray-green succulent foliage by long pink stems. ’Thunderhead’ is one of the larger sedum hybrids, growing to be up to 30 inches tall and 24 inches wide. This being said, it is not a very aggressive plant and likely will not outcompete other nearby plants. Butterflies, bees, and hummingbirds are common pollinators of this plant. This sedum hybrid has a much shorter bloom time compared to the previous two plants, with blooms beginning in August and ceasing in September. They won’t be around for long, so make sure to stop by and check them out! 

Care information: These sedums prefer full sun and well-drained soil. They do best in zones 4-9. Since they have fleshy foliage, they don’t typically need as much water and are more drought-tolerant. With this being said, they won’t mind the extra drink if they can get it, so watering once or twice a week is ideal. These sedums are not high maintenance whatsoever and don’t require any fertilizer or special care to look as fabulous as they do. Spent blooms don’t even need to be deadheaded because they still look aesthetically pleasing all throughout winter (though you can remove them if preferred). 

For more information, reference our Gardens Explorer 
 

Caucasian Gentian (Gentiana paradoxa var. lagodechiana) 

These true-blue flowers can be found atop the most Southwestern berm of the Rock Garden. These flowers have fringes in between each petal, resembling a fraying cloth, making them look almost fake. Their trumpet-shaped blooms have white throats with purple streaks that attract the eye to the center of the flower. Though this flower is likely attractive to many pollinators, it is primarily pollinated by bumblebees due to its tight trumpet shape. Since there is such a small but deep opening to get to the reproductive parts, bumblebees must push their way into the flower, which many other pollinators do not have the strength or size to do. Compared to many other flowers in the Gentian Family (Gentianaceae), the flowers of Gentiana paradoxa are some of the largest. These blooms typically start in mid-August and cease around late September. Though this may seem like a late blooming season, there are some gentian varieties that bloom as late as November, such as Gentiana sino-ornata ’Bellatrix’. 

Care information: The Caucasian gentian is hardy in zones 4 through 10. It prefers full sun but can also do well in mostly sun. Well-drained soils are necessary as standing water can lead to root rot in these plants. Fertilization is optional, a balanced fertilizer can be added in mid-spring but is by no means required. They should typically be watered twice a week. Since one plant can get to be up to a foot wide and tall, plants should be spaced about a foot apart if clumping is desired, or 15 inches apart if separation is desired. Spent blooms can deadheaded throughout the blooming season to promote new blooms. The plant can be cut down to a couple of inches after flowering as well since most foliage will die anyway during the winter.  

For more information, reference our Gardens Explorer 

 
Montrose White Calamint (Clinopodium (Calamintha) nepeta 'Montrose White')

These small white blooms can be found scattered throughout our Fragrance Garden. If you want to attract pollinators to your garden, this is a must-have. At any point in the day, there are dozens — maybe even hundreds — of bees flying from bloom to bloom on each and every one of our bushes. This is likely because of its abundance of nectar-rich flowers that can keep them occupied without moving great distances. These blooms typically last all the way from June to October, so they keep the bees happy for the whole summer. This dense plant brings a unique texture to gardens, especially when planted near plants with larger, sparser foliage and blooms, such as the sacred datura. The minuscule foliage is very fragrant, especially when crushed, which is common in the mint family (Lamiaceae). If you have issues with deer eating your plants, you’ll be happy to know that they won’t come near these guys.  

Care information: Montrose white calamint is hardy in zones 5 through 9. It prefers full sun but can handle part shade, as long as it’s during the afternoon. Soils should be well-drained to prevent standing water, but clayey soils are still fine. Calamintha nepeta ’Montrose White’ can get to be around 3 feet in diameter, so it’s important to leave it enough room to avoid competition with other plants. Height, however, is less of an issue since stems spread much more laterally than they do vertically, only growing to be about a foot tall. Deadheading is absolutely not necessary for this plant as there are way too many flowers to do so, however cutbacks are appreciated to maintain form and spreading. Though most other related species self-seed uncontrollably, ’Montrose White’ does not and is, therefore, much easier to control.  

For more information, reference our Gardens Explorer