I just love the unique look of these two Hoyas! They are both so easy to care for, just place them in your brightest window and water when dry! The perfect fit for someone who doesn’t want a fussy plant or needs a plant that can go awhile between watering.
Hoya Kerrii grows as a long vine that wanders and is best contained with a trellis, where Hoya Obovata seems to grow more compact and much slower. Both are said to be slow growers, but they can get quite big, so be sure you have the space for their future size. Both have very similar care, so I treat both of mine the same.
Potting: Hoya Kerrii and Obovata like to be snug in their pots, so wait until they are slightly root-bound before going up a pot size. Be sure to pick a pot that drains really well and avoid going up in size during the winter when growth slows down, they are easily over-watered. I would also suggest trying to train your Kerrii early with a heavy duty trellis or tomato cage. The vines are only pliable for a very short time, so I attach them to the trellis as they grow. Plan for your Kerrii to get quite large in the future. As for soil, its best to amend your basic potting soil for better drainage. For all of my Hoyas I make a mix of potting soil(like Happy Frog or Mother Earth), mini bark nuggets, and pumice, at about a 2-2-1 mix. I have found Kerrii and Obovata to do really well in this fast draining mix.
Light: Like all Hoyas, Kerrii and Obovata like a lot of light. I keep mine directly in my ESE window and they do really well. I tried the Kerrii in a NE window and it started to stretch and show signs of not getting enough light, so I moved it back to my brightest windows. In high light, my Obovata gets a beautiful silvery splash to it that I just love. If you are wanting your Kerrii or Obovata to bloom, high-light is a must! A note on blooms, Kerrii blooms weep nectar profusely so be sure to have something under it to catch the drips.
Watering: Hoya Kerrii and Hoya Obovata are really easy to over-water as they like to dry out quite a bit between watering. I wait until they are fairly dry and then water deeply until water comes out the drainage holes. If you are using a really bark heavy mix like I do, you may have to pour several cups of water through it so that the bark can soak some up.
Fertilizing: I fertilize all of my Hoyas weakly with every watering. I use Dyna-Grow’s Foilage Pro at a quarter strength. Just recently I have switched things up and am using their Orchid Pro to try and get my Hoyas to bloom.
Propagation and Pruning: Propagating Kerrii and Obovata is really easy. Just cut a piece off any vine, making sure to have at lease one node. From there you can root your cutting in water or a fast draining mix. If you root them in potting mix, don’t let the mix get really dry until the cuttings have a good root system. I prefer to root my Hoyas in water until they have just the start of roots, then transfer them to soil. When you pot up your cuttings go with a small pot so you reduce the risk of over-watering. A quick note on propagating Hoya Kerrii, these are often sold as single leaf cuttings around Valentine’s Day. It could take years, but they can eventually become a large vine if they have part of a node with their roots. If there is no node cells, then it will just be a rooted leaf. They can live for many years as a Zombie Leaf and are totally adorable!
Hoyas are very slow gowing, so it will be awhile before you need to prune them back. But if you do want to prune yours, simply cut the vines to your desired length, about an inch above a node. Have a rag handy, Kerrii and Obovata bleed a lot of white sap when they are cut.
Toxicity: Hoya Kerrii and Obovata are considered non-toxic to dogs, cats, horses, and people. However people with a latex allergy should take care when pruning or when there is sap running.