Planning a Mass Planting:

To plan for a mass planting, first you must know how much space you are about to plant, measured in square feet. Multiply the length of the garden by its width (all measured in feet). This figure will be the area of the garden in square feet.

Example:
Length = 15 feet
Width = 5 feet
Total = 75 square feet

When using the following charts, find the factor that will calculate the total number of plants for the garden when multiplied by the garden’s square footage.

Plant and Bulb Spacing:

Number of plants or bulbs per 100 square feet if planted on:

Square Spacing:

02” centers = 3600 (36 per sq. ft.)
03” centers = 1600 (16 per sq. ft.)
04” centers = 900 (9 per per sq. ft.)
06” centers = 400 (4 per per sq. ft.)
08” centers = 225 (2.25 per sq. ft.)
12” centers = 100 (1 per sq. ft.)
15” centers = 64 (.64 per sq. ft.)
18” centers = 45 (.444 per sq. ft.)
24” centers = 25 (.25 per sq. ft.)
36” centers = 12 (.111 per sq. ft.)
48” centers = 07 (.0625 per sq. ft.)

Triangle or Zig-Zag Spacing:

02” centers = 4150 (41.5 per sq. ft.)
03” centers = 1782 (17.8 per sq. ft.)
04” centers = 1000 (10 per per sq. ft.)
06” centers = 461 (4.61 per per sq. ft.)
08” centers = 263 (2.6 per sq. ft.)
10” centers = 166 (1.66 per sq. ft.)
12” centers = 115 (1.15 per sq. ft.)
15” centers = 74 (.738 per sq. ft.)
18” centers = 51 (.512 per sq. ft.)
24” centers = 27 (..27 per sq. ft.)
36” centers = 19 (.189 per sq. ft.)
48” centers = 08 (.0725 per sq. ft.)

Round Beds:

Round beds require a bit more effort to figure out. Below is the calculated square feet for certain circular sizes. Decide on the method of planting desired, the spacing required for the plants, and multiply to get the estimated number of plants required.

Diameter in Feet

The following example shows what a round bed 12 feet in diameter of Giant Liriope would require for complete coverage at 18 inch zig-zag spacing.

Example:
Plants per square foot 000.512
Square feet in bed 113.
Total plants needed 58.

Note: You can use larger spacings, but the longer the plants take to cover the ground, the longer you have to keep weeds from taking over the planting...

Soil Preparation 101:

When preparing beds for planting you must first make sure you have a good loam that contains a proper amount of organic material. One way to test for a good loam is by making a ball (about the size of a golf ball) with the soil. Squeeze the soil with your thumb and the middle part of your index finger, making a ribbon with the soil. This will tell you if you have a high clay content or a loam content. A high clay content will not allow water and nutrients to be absorbed properly and cause them to run off. Gypsum is one way to combat this clay content. Adding 40 pounds per 1000 square feet will break down the clay naturally. Adding a 2 inch layer of compost, such as Back-To-Nature or humore is another way to work on this problem.

It would be a good idea to have your soil tested by a local testing facility or by the Texas Department of Agriculture. This test will give you an accurate test on the available N, P, & K in your soil. There are also very inexpensive soil test kits that can be purchased at Alldredge Gardens. PH is another aspect that must be considered when preparing beds for planting. Much of the soil around the Lubbock area is a, somewhat, Alkaline soil. To reverse the effects of this problem Iron can be added to your beds. Iron comes in many forms and formulations. Liquid forms of iron can be applied as a foliar feed or added to the soil at a diluted rate. Granular forms, such as Iron & Soil Acidifier, Ironite, Ionate Plus, Copperas and Micromate are good sources of Iron that when used properly will not burn or cause plant material to rust. A good planting media is essential for proper plant growth.