
Planting between stones can be the simplest way to give your pathway or patio that “finished” lived in, been there a while look you desire in your garden.
But how do you exactly calculate the number of plants needed for a path?
On our site www.stepables.com, we have added an entirely new section call the STEPscapes Design Center to help homeowners create their own masterpieces on the ground. One feature to help homeowner’ is the plant calculator. It will help you determine exactly how many plants you need for a complete planting of STEPABLES®.
However, calculating an area that has stones running through it is completely different.
I wish there was a simple way to calculate planting cracks…but there is not.
Every stone is different, every garden path ranges in size and all of our STEPABLE® plants have different growth rates.
The first decision you will need to make is to decide how much to budget for this project and how long do you want to stare at bare ground.
It really does come down to that.
Big stones and lots of plants = little to no maintenance and a happy face. However, the same big stones with few plants will be something you will need to maintain, weed and watch with disdain as it slowly fills in. You will either spend time weeding, applying herbicides to keep the weeds down or end up spreading bark/mulch.
Any way you slice it, you will need to do know what you are willing to spend verses how much work you will be willing to do afterward to decide how much to allow for the entire project.
Below are a few time saving/money saving tips that I hope will help in you decision making process.

1. Many STEPABLE® plants can be sliced up to fit smaller spots.
For example: Say a plant is roughly 3″. When cutting it almost in half (leaving a bit together as a hinge), you now have a 6″ piece that is a 1.5″ wide. Depending on the size of your opening, you might be able to simply drop it in at this point.

Next: you just need to calculate the crack line. (No I am not laughing as I am writing this.) To get this estimate, you will need to know what stones you are going to use and how big they are. Slate can be as big as 6 feet long and 3-4 feet wide, while brick may only measure 3”x 8”. You will also need to estimate how many total stones you will be using in the area to complete the project.

I usually tell folks to plant 1-2 plants one each side of every stone-depending of course on the size of the stone. Big slate may be up to three, four or five plants.
So let’s go very simple here: if you are figuring 100 stones, times four plants (one for each side) = 400 plants. Now, if you divide your plants, you will only need 200 and if you quarter them you will only need 100.
Note: By dividing/cutting your plants, you run the risk of shocking them or worse, forgetting to water them. You should consider how good of a gardener you are before doing this. Only do this is you are going to monitor the area all of the time and will keep them well watered so the little chunks don’t dry out. Apply a fungicide as well after planting to help thwart off disease due to stress. Be honest. If you don’t have the time to garden, give the plants a break and plant whole. Don’t run the risk of losing your plants to save a few bucks. It’s just not worth it.
2. Another factor is plant growth speed. STEPABLE® growth rates and spacing have been deliberately set for a calculation of filling in roughly within one year. This is in the free and open range-so in cramped quarters; the plants may alter their growth a bit.
Fast growth rate plants fill in quickly. Yeah!!! You can use less of them to fill in your area!!! However, keep in mind that they are fast growers. You will have more maintenance to deal with over your stones, as they will cover the stones faster than the slow plants. You will need to whack them back more often to keep your stone area attractive and useful.
On the other hand, slow growing plants take more time to fill in. You will need to buy more plants to fill in the same area in the same time frame. However, you will have super low maintenance issues in the long run and a more hassle-free zone.
Tip: If your budget is tight, allow for fewer, but much larger planting pockets in the stone area. This will enable you to still have the look you want, but reduce the need to plant every side of every stone, which will save you money.
3. Stone selection will be extremely important to the success of your plants. 
The larger the stone, the more foot traffic the stone will take. The smaller the stone, the more foot traffic the plant will take. The moral of our little story: Choose wisely grasshopper! If you choose poorly, you may end up with an area that is frustrating to walk through, performs poorly, and doesn’t fit your needs.
4. Planting the gaps: How much area do you leave for planting? If you leave a 4” gap between stones, you will be good to go. If it is a preexisting path, then cutting the plant will be necessary. 
5. Planting medium: Sometimes you have a choice in this and sometimes you don’t. I recommend a mixture of sand or gravel (which is usually the base for the stones anyway) with any good soil blend that is recommended for your area. You will only need to go 3-4” down, but 6” is usually best. This will allow for great drainage and keep enough moisture for the plants not to dry out.
Tip: If no soil is available and only gravel, try sedums. They are the champions of crummy environments.
So, to recap: Planting your stone area really depends on your budget, the size stones you get, speed of plant growth and the amount of area left for planting after you place your stones. Remember to research your STEPABLE® plants and decide which plant will be take the right amount of foot traffic, the right amount of light to the area and the right amount of water.
Setting stone is one of the best ways to improve your landscape. Planting STEPABLES® correctly between the cracks will create a fabulous “lived in” look to your pathways and patios and give you years of satisfaction.
That’s it! I have to go prune roses.
Now go get dirty!
Fran
www.stepables.com