The Hoya Wilbur Graves, also known as the Hoya Carnosa ‘Wilbur Graves’ features beautiful foliage on vining stems. The biggest difference between the two is the Wilbur Graves has tiny silver specks of silver, like silver paint, splashed across its rig green leaves
A member of the Apocynaceae family, like all Hoyas, this collectors prize is also epiphytic in nature. Like their distant cousins, orchids, they make perfect house plants but require special care.
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A Collectors Dream
The main thing that sets the Wilbur Graves apart from the Carnosa Hoya is that the silver splashes on its leaves. Like the Carnosa, it also bears beautiful flowers that grow in clusters.
Regrettably, the Hoya Wilbur Graves is an extremely rare species. This makes it extremely difficult to locate, even through online sources. And if you find one, they can be incredibly pricey, usually around $100 or more. Sometimes, the only thing you receive for that money is the stem cutting.
However, if you can snag one for a reasonable price (or even better, as a present), it will be a welcome addition to your home.
Though fairly resistant to disease, this Hoya has some very specific requirements for optimal growth. Light, proper soil, and controlled watering are essential to its health. Despite that, the Hoya Wilbur Graves is relatively easy to manage, and well worth the results.
What does the plant look like?
There are a number of videos featuring the Wilbur Graves if you’re looking to see it “in action”:
And in this video about Hoyas the plant is featured:
And in this one as well:
How do you take care of the plant?
Organic matter like coco coir and drainage aids like perlite or vermiculite are hallmarks of high-quality soil. The solution is as simple as mixing in some perlite to your ordinary bag of potting soil from the supermarket.
Soil that is light, airy, and well-draining is ideal for the Hoya Wilbur Graves because this plant is susceptible to root rot when over-watered. Soil must contain just enough water to protect the plant from drying out while allowing excess moisture to drain.
Heavy soils or soils that retain a lot of water are to be avoided since they cause the roots to sit in water for extended periods of time, which increases the likelihood of root rot.
Thankfully, there are a variety of approaches to achieving this middle ground. You can choose from the following suggestions.
Any of these are a good option if you’re looking for a commercial blend:
- Light potting soil
- African violets soil
- Orchid mix
If you don’t have organic potting soil on hand, normal potting soil will work in a pinch. Perlite should be added to improve drainage.
If you can, avoid sandy areas. Despite its beneficial effect on drainage, sand eventually gets compacted. This can become a problem over time because hoyas don’t need to be repotted very often. If you must use sand, you will need to repot your plants every year.
When I produce my own soil, I can ensure that it drains well and is a touch chunky, which increases air flow to the plant’s roots. Peat moss, perlite, and pine bark are my preferred mediums. You can also include Coco coir chips, pumice, and loam-based compost in your planting mix to enhance drainage.
How often do you water the plant?
Hoya ‘Wilbur Graves’ prefer dry conditions and should only be watered lightly to ensure its success. When grown in indirect light and housed in a 5.0″ pot, Hoya ‘Wilbur Graves’ requires only 0.8 cups of water every 12 days.
If you want to keep your Wilbur Graves looking their best, avoid over-watering them or watering them too often. Even though it requires water, especially during the growing seasons of spring and summer, it cannot survive in very damp or waterlogged soil.
To achieve this, allow the soil to dry out slightly between waterings.
How much light does the plant need?
Wilbur Graves loves light, but its leaves burn in direct sunshine. It can thrive in dim light, making it a good inside plant. Keeping it in a dark or windowless room will limit its growth.
This plant loses leaves without enough sun. South-facing windows are ideal. East, west, and south-facing windows give your plant natural sunlight. The warm morning sun from the east requires only putting an object near a window. West and south residents should screen their lawns and gardens from the afternoon sun.
Strong fluorescent illumination for a minimum of 12-16 hours per day can keep it content.
How do you prune the plant?
The stalks that bear flowers on this plant are called peduncles. cutting off the stems that have peduncles (sometimes called spurs) will not result in blooms.
Minimal attention is needed for this plant that spreads rapidly as a vine. Pruning is mostly for show and leaves should only be trimmed if they are discolored or damaged.
Is there anything I can do if some of the plant’s leaves are turning yellow?
In most cases, the issue is caused by excessive watering or high interior humidity. Humidity levels in many homes are between 30% and 50%.
How do I propagate the plant?
Hoya Wilbur Graves propagates best from stem cuttings. Use tender stems with at least two leaves. Cut a 4- to 6-inch portion of the stem using clean shears.
Plant it in well-drained, new soil. If desired, dip the cutting in rooting hormone. The cutting should root in three weeks. Next month, you’ll see the first shoots and leaves.
Plant propagation is best done in spring and summer.
When should I repot the plant?
When the Hoya ‘Wilbur Graves’ has doubled in size, or once a year, whichever comes first, repot it. So long as you replace your potting soil every year, your plant shouldn’t require any more fertilizer. It’s important to keep in mind that fertilizer isn’t what gives plants their energy. The sun is.
What kind of fertilizer do I need for my plant?
Only in the spring and summer should you give your Hoya Wilbur Graves any food In the fall and winter, it goes into dormancy after a year of rapid growth, so you don’t have to worry about feeding it.
Once a month, I prefer to use a water-soluble fertilizer that I have diluted to half strength. A balanced one works well (15-15-15) although other options I’ve tried that work really well are 2-1-2 and 3-1-2 N-P-K formulations.
More Nitrogen, which is good for plants, means a higher first number (foliage development). However, a 5-10-5 mixture should be used instead if the plant isn’t producing enough blooms. This one has more flowering-inducing phosphorous.
What are some common problems for the plant?
In most cases, improper pruning is to blame.
Although the plant is pest-resistant, take measures. Monitoring and quick response are key. Mealybugs, spider mites, aphids, and scale progressively damage plants. Their growing numbers threaten to harm the plant.
Therefore, it should be treated immediately upon detection. Neem oil and insecticidal soap are both useful remedies. However, the longer it takes to finish treatment, the more bugs there are to begin with.
The Botrytis blight, sooty mold, and root rot are all problems. The first is a fungus, the second is a mold, and the third results from roots being submerged in water for extended periods of time.
How big does the plant get?
This plant generally comes in cuttings or 3.5-inch pots. This is a relatively small house plants but size depends on how long you allow its stems to grow.
Can you grow the plant indoors?
It is important to check indoor humidity and have the proper lighting. Other than that, this is a perfect house plant.
Can you grow the plant outside?
To some extent, this Hoya can tolerate direct sunlight when grown outside. But only in the spring and the autumn! Summer’s intense sunlight is simply too much for it to withstand.
In USDA Hardiness Zones 9–11, it will thrive in the winter sun. Because it cannot survive freezing weather or snow it’s best to keep it indoors, especially if you live somewhere chilly. Otherwise, during the warmer months, a site with either some sun and some shade is excellent for its protection.
Is the plant rare?
Collectible Hoya Wilbur Graves are rare. They can be hard to find, even online. If you find one, you’ll spend $100 or more.If you can buy one (or get one as a gift), it will look great in your home.
Where to find the plant for sale?
You can generally find the Wilbur Graves on online sources such as Amazon, EBay, or other specialty web sites.
Beautifully splashed silver foliage distinguishes the Wilbur Graves, which is often misidentified as a Pubicalyx. This Hoya plant can be hard to come by due to its rarity, but it would be a stunning centerpiece for any garden.
Frequently Asked Questions
Additional Sources & Resources
-Smithsonian Institution. (n.d.). Hoya carnosa ‘Wilbur Graves’. Retrieved March 09, 2021, from https://www.smithsonianmag.com/smart-news/hoya-carnosa-wilbur-graves-180973455/
-The Flower Expert. (n.d.). Hoya Plants. Retrieved March 09, 2021, from https://www.theflowerexpert.com/content/aboutflowers/floweringplants/hoya
-Wistuba, A., & Dittrich, P. (2002). A revision of Hoya R. Br. ex Aiton (Apocynaceae: Asclepiadoideae). Sendtnera, 9(1), 1-102. Retrieved March 09, 2021, from https://www.researchgate.net/publication/232869429_A_revision_of_Hoya_R_Br_ex_Aiton_Apocynaceae_Asclepiadoideae
-Chase, M. W., & Coddington, J. A. (1990). DNA evolution in Hoya (Apocynaceae). Systematic Botany, 15(4), 537-543. Retrieved March 09, 2021, from https://www.jstor.org/stable/2419424?seq=1
-Liogier, H. A., & Martorell, L. F. (1982). Flora de Puerto Rico y adjuntas islas Sabana y Mona (2nd ed.). Río Piedras: Editorial de la Universidad de Puerto Rico. Retrieved March 09, 2021, from https://books.google.com/books?id=YJ_xAAAAMAAJ&newbks=0&printsec=frontcover&dq=hoya+carnosa&q=hoya+carnosa&hl=en
-Sánchez, J. A., & Freytag, G. F. (1993). Woody plants of Puerto Rico and the Virgin Islands: a descriptive field guide (Vol. 2). Austin: University of Texas Press. Retrieved March 09, 2021, from https://books.google.com/books?id=qlAvAQAAMAAJ&newbks=0&printsec=frontcover&dq=hoya+carnosa&q=hoya+carnosa&hl=en
-Woodson, R. E., Jr.. (1954). The Apocynaceae of Panama. Annals of the Missouri Botanical Garden, 41(3), 271-429. Retrieved March 09, 2021, from https://www.jstor.org/stable/2395646?seq=1
-Steyermark, J. A. (1963). Flora of Missouri. Ames: Iowa State University Press. Retrieved March 09, 2021, from https://books.google.com/books?id=mwkKAQAAMAAJ&newbks=0&printsec=frontcover&dq=hoya+carnosa&q=hoya+carnosa&hl=en
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