I'm not sure what you mean by "tolerate irregular watering", but my definition means sure death to any plant eventually. Are you unable to check them regularly so they tend to get dry, or are you inclined to over-water? There are Hoyas that like to be a bit wetter, and there are Hoyas that are fairly succulent and tolerate drying, so your answer can make a world of difference in the responses you'll get.

Denise in Omaha

Irregular watering is watering about every week and a half in my book

Watering them right is probably the most critical part of keeping them healthy, and "often enough" depends on a lot of things... the kind of soil they're in, the size of the pot, how much light they're getting, how warm their surroundings are, time of year, whether it's a thin-leaved or succulent species. For example, Hoya kerrii is a very succulent species, relatively easy to grow. In the winter when it's cool and they aren't getting a lot of sun and heat, every 10 days may be too much water, but in the summer months, it wouldn't be enough. So I'll suggest what I consider easy species not based on watering and just say they should be watered when they approach dryness, whether that means in 4 days or in 3 weeks...

kerrii*
lacunosa
vanuatuensis
pubicalyx cultivars
diversifolia*
brevialata
javanica (or multiflora)
lobbii
micrantha
obovata*
pottsii
australis
wayetti

The * species are ones that can be grown in hanging pots but have to be diligently trained if grown that way as they have very thick vines that turn hard as they age.

Denise in Omaha

Thank you Denise, I have heard of all of these species. My criteria was to strict. I should of put that exeptions are allowed if they are still easy.

TG in Albany

Your third Hoya is probably Hoya tsangii but feel free to change the tag to Hoya sp DS-70 as tsangii is a misnomer for that plant.

Have you considered growing in semi-hydroponics so that the plants have a supply of water to get them through? Not watering at the proper times will make it very difficult to grow many species. If you occasionally forget to water plants will survive but if you do it often many will not grow well at all and they will be unlikely to bloom.

Mike

The nice Swedish lady that created the Hoyor website has put a ton of care information (such as drought tolerance) for many different hoya species-

The website www.myhoyas.com is really great, too.

Here is a link that might be useful: Hoyor.net

I'm glad Mike brought up semi-hydro - it's a great solution for someone who doesn't want to mess with "feeling" all their plants for dryness every few days. If you use the designated pots and their water guage, all you have to do is look at the gauge and add water as needed. I find a lot of species thrive this way. I'll put a link to where I buy my pots & accessories.

Denise in Omaha

Here is a link that might be useful: Hydro pots

Teengardener, try Hoya Shepherdii. One of the easiest cool-growing Hoyas to grow.