WINDOW BOXES 101

Here are our DON’Ts:

1. Don’t plant perennials thinking it’s once and done. Perennials will outgrow the space, and just because they survive cold winters planted in the ground does not mean they will survive winter in a window box.  The roots will not be insulated by the ground and survival is less likely. 

2. Don’t overplant it.  Make sure to leave room for growth. 

3. Don’t forget to water it if it is not automatically irrigated. Be sure to soak the roots (water until water runs out the bottom) when the soil is dry one inch down.  This is likely to be at least every other day, depending on weather and location. 

4. Don’t use just any old soil.  Use a good potting mix ideally with slow release fertilizer (such as ProMix) for best results. 

Here is our advice:

1. Plant annuals once danger of frost is gone (typically end of April/early May, when 2-week forecast shows nighttime temperatures staying in the 50s).  Spring/summer annuals will survive until first frost if you care for them.  In autumn (late September/early October is best so they have time to establish roots before the frost) you can replace them with pansies, ornamental cabbage, snapdragons, dianthus, or other cool weather annuals that will survive through to spring.

2. Check how much sun the boxes get daily so you can choose the right plants.  If they get more than 6 hours of sun and face west or south, you want to choose heat tolerant plants. 

3. Know if there is irrigation or not, and make sure the window box is adequately watered but not overwatered. Make sure there are drainage holes.

4. For the healthiest plants, replace all potting mix each year.  At the minimum, mix the soil and top off last year’s with fresh potting mix and slow release fertilizer. The formula to figure out how much potting mix you need is length in inches multiplied by width in inches multiplied by depth in inches, divided by 1728. That will give you the number of cubic feet of potting mix you need to fill it. (L”xW”xD”/1728=cf)  

5. Leave room for flowers to grow.  Usually planting every 5” - 6” fills them in nicely in a short amount of time.

6. A mix of thrillers (tall flowers), fillers (lower spreading flowers), and spillers (greenery or flowers that cascade over the sides) is usually recommended.  Many people use only fillers and spillers for window boxes so they don’t obstruct their view from the window. But feel free to choose whatever you like! Think about the colors you want up against your house and what it will look like for curb appeal.

7. We have everything you need to make your window boxes pop!  Stop by or email us with any questions you have.