It’s always a great idea to top-dress any new plant installs with fresh and fluffy soil amender. The newly planted beds get an instant dark look and the plants benefit from having new soil amender close by. At roughly $30 per yard it’s money well spent.
Key idea
When you install fresh soil amender your bed looks nice and fluffy. Congratulations! But you must not forget that the soil amender will settle. I got a reminder of this recently when I had to re-do a bed where many plants were planted too high. What really happened was that the soil amender came in first before the plants; and the young dudes doing the plant install failed to properly account for settling.
This Spirea japonica is clearly sitting too high after the amender settled.
This is better.
When you bring the amender in from your local supplier it’s dark, fluffy and beautiful but eventually it settles as it loses it’s fluffiness. So if you’re planting in this kind of situation, remember to adjust for settling. Otherwise, you will be like me replanting several specimens that are clearly sticking up and showing their roots.
Native soil
It just so happened that I was installing new plants next door to this area and on this day the plants came first; then we brought in soil amender for top-dressing. This approach has obvious advantages. One, the plants are planted in native site soil, not in fresh soil amender; and two, the planting level is obvious so we don’t have to guess at future amender settling.
Once you’re done top-dressing, it’s always a good idea to water in your new plants. Also, if the soil amender is still warm, try not to pack it directly around the plant stems. Instead, leave a bit of space between the plant stems and soil amender.
Finished plant install in native soil, before soil amender application.
After soil amender and watering. This frequently used staircase area now looks much better.
Conclusion
Soil amender settles over time so try to plant in native soil and then top-dressing. Planting directly in soil amender means that your plants could be sticking out too much once the amender settles.
Always top dress your newly planted beds with soil amender because they look better and it benefits the plants. Water your new plants in.
