Landscape Project 21-1: East Pergola

I have had lots of problem areas with my backyard. It’s on two levels – half on a lower level coming out of my house and roughly half on an upper level nine foot higher in elevation. The two are separated by a 45 degree slope which I have terraced in a red intermittent concrete wall and covered the slopes with five different sized round rock. The effect is good as it provides ample space for unique plantings and is a favorite playground for grandkids. The bottom of the slope is anchored by a 2 1/2 foot tall railroad tie wall covered in a close knit dark brown trellis.

At the eastern corner, I doglegged the retailing wall extending it downslope about twelve feet to provide for a 10 foot square concrete pad which is covered with a pergola and houses our hot tub – a favorite relaxation focus.

All of that is a project past and although it is not entirely complete, it serves a purpose of preventing erosion and serving as a planting challenge each spring. So what’s the current issue?

Well, the railroad tie dogleg interior was never really finished. It has an interior slope from 30 inches to about 16 inches above the lower backyard. and covers a roughly 12 foot by 12 foot area that is now sodded but difficult to mow. It just doesn’t look finished so here is what I am going to do.

I will raise the area another six inches which will provide a planting depth of 24 inches in the deeper area and a minimum 6 inches in the shallow hillside perimeter. I will plant some medium height colorful shrubbery which will act as a hot tub screen to the east and left. This will be a level area with a height consistent with the existing retaining wall but six inches higher.

This photo is before hot tub was placed. Area in question is at the center left. Camera lens distorts 6×6 cedar posts as they are actually straight up and down – not slanted! Note pergola roof cover which filters sun from the west and right. Terraced and rocked hillside to the right center.

First thing to do is evaluate the area environmentally. It will receive full morning sun and filtered sun (through my covered pergola) sheltering the area from the hot afternoon sun in mid-summer. Wind is not a factor as a six foot privacy fence keeps surface winds to a minimum. Moisture will be semi-controlled with full access to overhead and eastern rain and semi-sheltered (pergola again) from heavy western rains. Water coming over the hillside will be absorbed in the rock/terrace hillside and any excess will be diverted by a new concrete waterproofed block wall on one side. The pergola side will also be waterproofed to prevent excess water seepage from spreading over the three foot wide deck around the hot tub.

Hot Tub being installed last Fall. The landscaping project is in the lower part of photo.

To raise the level of the area, I will attach a 12 foot pressure treated 6X6 to the retaining wall top along the hot tub deck side and the bottom of the hill side,

The base soil is typical red Georgia clay not conducive to the plants I want so I will fill the area with a site mixed combination of garden soil, mushroom compost, and light potting soil. Cost is a concern but relatively minor factor since I want to get it done and it will add considerable aesthetic appeal to the hot tub pergola area, give it a finished look, provide screening, and a touch of color.

Three red Oakleaf Hydrangea will provide the main planting focus. I have to plant them far enough apart. Nursery says they will grow to a 4x4x4 foot mound,

So lets look at my choice of plantings. “Begin with the end in mind” is a favorite maxim. I am developing a backyard theme of state by state wildflowers and two will be featured here. The Oakleaf Hydrangea is the state flower of Alabama and the Lilac is the state flower of New Hampshire. The hydrangea grows to a 4x4x4 rounded cube and the lilac is slightly larger reaching a height of six feet. Three hydrangea have been purchased along with two lilac bushes from my favorite nursery – Twin Branch in Woodstock. In the shallower area on the periphery I plan to purchase six medium sized Hosta with a bright green leaf with just a touch of red. A three inch cover of black mulch will pull the plantings together and provide moisture and temperature control.

The Cream colored Lilac will grow six feet tall and provide a contrast to the red hydrangea.

So what will the cost be?

Plants – 3 gallon hydrangea at $25 each, 2 lilac at $25 each and six Hosta at $70. The Hosta are relatively expensive but the red-blushed leaves are unique and the plants will provide future cuttings. Total plant cost – about $200.

Six red-tinged Hosta will complement the Oakleaf Hydrangea and provide a transition from hillside to taller shrubs.

Soil – I will need 22 bags of garden soil, 4 bags of mushroom compost, and 3 bags of potting soil and about $6 each for a total cost of about $180.

The 6×6 12 foot lumber was already on hand from a previous project and, if I remember correctly, were about $25 each (much higher today). I will need some 10 inch spikes to anchor the 6×6 onto the retaining wall, several cans of dark brown spray paint, and and black landscape fabric for weed control, plus some tar paper for water diversion. Most of that is on hand but may be an extra $20 or so,

The concrete red block wall material is on hand and I paid about a dollar apiece for them and I will use around 30 or so to raise the final level the six inches on the upper slope side. Total cost, then, will be around $400.

Labor is estimated at eight hours to raise the bed, mix and spread soil, plant shrubs, and spread mulch. So let the project begin!!!

The first half of the new soil mix is in place. Shrubs were temporarily placed to judge depth. The red concrete block wall will curve around the left corner and join the existing terrace on the hillside. Note the pergola sun filter over the hot tub which will create partial shade from hot afternoon sun. Hot tub is to the right. A 6×6 12 footer will go atop the retaining wall at bottom and be painted dark brown.

A better view of the planting area. One 6×6 is in place and one will be laid atop the front retaining wall raising the planting area by six inches. Plants are there only to gauge the final bed height.

Just waiting on blooms!~~~