Answer: These are probably some type of the hardy shrub hibiscus or Hibiscus syriacus, there are many different cultivars available. This shrub is considered hardy into zone 5, however your zip code places you in zone 5A or the coldest part of zone 5. Depending on your microclimate, it may be as cold as zone 4. For this reason, this may not be the best choice of shrub for your area and may explain why they did not overwinter for you. It may also explain why they are not widely carried in your area. I would suggest you ask your local professional nursery staff and/or county extension to help you identify some possible substitutes that you could plant instead. Alternatively you could search a bit further from home. There is a zip code based dealer locator at the Monrovia web site to help with contact information.
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