Hi Ameris,
Can you share a photo of your
Sweetheart Hoya (Hoya kerrii) in it's nursery pot, without the green and tan colored pots that it appears to be sitting in? What type of soil is being used and how much light is the plant receiving indoors? When repotting, fine feeder roots are often damaged during the process and the plant may take awhile to recover but I'm curious to know what type of soil is it planted in. You say "
I took the plant out of the mud to help dry it out." The term "mud" is concerning because mud is very dense and soggy, not at all conducive to a healthy plant and the exact opposite of what Hoyas require to survive. Did you allow it to dry out and then plant it back into that same "mud/soil"?
For health and longevity, Hoyas need excellent air circulation around their roots, so a light and airy potting medium that dries quickly is very important. I've always used a combination of a small amount of potting soil with lots of perlite and orchid bark, or coconut husk chips mixed in. Some growers use potting soil with lots of Leca (lightweight clay pellets/balls) and perlite added and some use no soil whatsoever, only the clay pellets. A light media may mean you have to water more often but it replicates how the plant would grow in nature. Being planted in a dense soil will deter aeration and drainage, which leads to root suffocation and rot.
I'd advise repotting into a small plastic nursery pot with lots of drainage holes and using a light, airy potting medium. Your profile doesn't show what part of the world you are located but I'd suggest placing the pot in a warm, bright location that has good air circulation and be very careful with watering.
The milky white sap is perfectly normal. Hoyas are in the same family of plants as Milkweeds whose stems and leaves contain a latex sap; when a stem breaks or leaves are damaged by a small nick, or a leaf breaks, the area oozes the white sap. The sap is said to be toxic so be aware if you have pets that like to lick. It can also cause contact dermatitis (itchy rash) in some individuals. The blooms of many hoyas will exude a clear nectar that attracts pollinators but that is different than the white sap in the stems and leaves.
