Concerning the heavy (plastic?) sheets used on beds around shrubs, etc., I assume water passes through that material, but I wonder if fertilizer passes through it when watering. Have just used slow release pellets around azaleas and then learned that material was deep under layers of dirt and mulch. I just can't do the every two weeks liquid fertilizer. Please tell me the fertilizer from the pellets will pass through this barrier!
Certified GKH Gardening Expert
I would say first determine what type of weed barrier you have - landscape fabric allows for both airflow and water (plus fertilizer) easily, while black plastic does not. If you have landscape fabric, then there shouldn't be an issue with the fertilizer passing through, especially if you are wetting it well and following label instructions. There are many fertilizers available so finding one that works shouldn't be difficult. That said, you could always choose to add compost around your plants or mix it into the soil around them. This works well for fertilizing many types of plants. If black plastic is what you have, you should either remove it and replace with something else (like breathable landscape fabric) or add small slits (about 2 in) at the area nearest each of your plants so that the fertilizer can get through these areas when watering (or from rainfall).