Holes for Planting
When planting a tree, shrub, garden bed or container garden, the depth and width of the hole can mean life or death to your new plant. Plant too deep and you create a basin that can collect too much water. Root rot may result and you can lose the plant. Plant too shallow and the roots may dry out or, in colder climates, the soil can push a tree or shrub right out of the ground during winter freezes and thaws.
Roses are especially sensitive to planting depth. In warmer zones, plant so the bud union — where the canes connect with the roots — is at or just above soil level. In colder climates, plant the union 4 to 6 inches below soil level, depending on the severity of your winters.
In addition to the right depth, the planting hole must also be wide enough to allow space for root growth.
In the Southwest, you may encounter caliche, a concrete-like soil deposit. These layered deposits of calcium carbonate restrict roots, increase soil salinity and reduce the plant's ability to take up iron, which is an essential nutrient. If your soil contains caliche, dig a slightly wider planting hole. Remove the caliche and add a quality planting mix to the hole. If caliche prevents digging a hole as deep as the root ball, opt for a smaller plant. Make sure the roots are covered with soil; they should find a foothold as the plant matures.
Holes for Decks, Fences and More
It’s essential that posts of any kind are plumb. For projects such as decks or fences, make sure the hole is vertical rather than angled. The bottom of the hole should be level. The hole needs to be deep enough to support the structural needs of the project as well as meet code requirements. Use the proper concrete mix, gravel and other fill material for the hole. Allow the concrete sufficient time to cure before proceeding to the next step.
Digging out the footing area for a patio, concrete pad or retaining wall requires tamping and leveling for a solid foundation. Excavations for pond liners — especially flexible liners — must be smooth and free of jagged projections.
More Digging Tips
Whether you’re digging a hole for planting or for another outdoor project, there are some other factors you need to think about.
- Consider the location of septic fields and tree roots.
- Before you plant trees under overhead utilities, make sure the plant you've chosen won’t interfere with the poles or cables.
- Before you dig for fences or privacy hedges, check property lines and easements.
Granted, digging holes is usually not a lot of fun, especially if you've got a lot to dig. It helps if you have the right tools. Shovels, spades and forks are the most common implements. For bigger jobs, a digging bar, post hole digger, mattock or pick may be necessary. Power tools, such as tillers and augers, can actually make digging fun. Use the right tool for the job so that the tool itself can do most of the work. Pace yourself properly to avoid overexertion and sore muscles the next day.
Before beginning any excavation, call 811 to check for underground utilities.