Plants should be planted with similar plants that have the same soil, light, and watering needs. You shouldn’t plant a water loving plant like a hardy hibiscus (rose mallow) next to a dry loving plant like a yucca or sedum, or should you?
Well, there is a way to do this. Something I’ve just started to do. You need to be able to make the water moist only around the plants that need it. Obviously this can be done with spot watering from a can, but that can also be a hassle. A better solution is to just water the entire bed normally, make sure it has good drainage, but then around your water loving plants put the new water absorbant crystals.
Water absorbant crystals, crystals that swell up and store water then slowly leak it back out, are not a really new product, they’ve been around for a few years. However they are mostly relegated to potted plants, some potting mixes even have them already mixed in. And don’t get me wrong, they’re awesome for potted plants, especially hanging baskets that can be hard to water. However they’re also great for garden plantings as well.
Chances are we all have a plant in our landscape that needs more water than most other plants, and we all probably water when this plant needs it, rather than when everything else needs it. Or, this plant doesn’t get as much water as it could use, and so has stunted growth.
You can remove the mulch from around said plants, and sprinkle these crystals on the soil, then reapply the mulch. Additionally you can add them directly to the hole the next time you’re planting such a plant.
Often too, plants that need lots of water, tolerate lots of water. So you don’t really need to worry about overdoing it. Water loving plants like canna lilies or bald cypresses can grow in standing water (and love it) so perpetually damp soil isn’t going to rot their roots. Other plants that need large doses of water include hydrangeas (especially those with sun exposure), the aforementioned hardy hibiscus, grape, pumpkin, cucumber, gourd, and really most other plants with large leaf surfaces (the larger the leaf, the more moisture is lost during the day).
With these crystals a little goes a long way as well, you can do hundreds of square feet of garden with a single bottle. If you cannot find them locally, Amazon sells them.