Summer 2019 Hours: Open Mon-Sat 9-5 Closed Sundays

New Castle Gardens is the only area nursery with locally grown, OMRI plant starts. We also have flowers and perennials and all the amendments you need, not to mention local art!

Gift Shop

Trees & Shrubs

Gardening Supplies

Annuals & Perennials

Vote for New Castle Gardens as the ‘Best Garden Store/Nursery’ in the Post Independent’s 2019 Locals’ Choice Awards

New Castle Gardens

6501 CR 214 (Peach Valley Road)
New Castle, CO 81647

We are a smoke free nursery – No Fumar. For their safety, and that of our customers, please leave your pets at home.
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Find all of our Newsletters on our Garden Talk blog.

Plant Sale and Plant Swap

1/2 Off All Annuals & Veggies
1/4 Off All Perennials

Plant Swap Sat 7/20 at 10 a.m.

You are welcome to bring non-plant items for trade (e.g. homemade soaps, oils, salts, whatever!). There will be a “potting bar” set up with soil and terra cotta pots so you can plant your new items if you like. Or bring your own pot for trade/planting. House Plants 101 lecture will begin around noon. No admission fee, trade-only style (it is a Swap). Of course there will be more awesome plants for sale at the nursery if your juices really get flowing. Reach out to me or Ali if you have any questions. This should be an awesome event. The more people that come the more plants we have to trade!

1/4 Off for the 4th (select plants) 15% Off All Other Outdoor Plants

1/4 Off for the 4th

Petunias & Calibrachoas


Herbs & Veggies
15% Off All Other Outdoor Plants

July Garden Calendar

July is usually our hottest month and many gardening activities become maintaining, weeding, and even harvesting. However, you can still direct seed zinnias in early July. They like the ground warm before emerging, and, it’s fun to see how fast they show up – you’ll have a fresh bloom of flowers in the fall when other annuals are looking weary.


If we don’t get enough rainfall, be sure to deeply water your trees.
Check the top and outer leaves of trees and shrubs for drought injury.
Pine needles turning brown on the part of the branch closest to the trunk is normal; but look for browning on the tip of the branch. It’s a sign the tree is in trouble.


July is a good time to apply fertilizer to your lawn. We use Pro-Rich, which is naturally based and does not have an herbicide for broad leafed weeds (which has been linked to cancer in dogs).
Apply, or reapply mulch; it helps prevent soil compaction, retain moisture and keeps the soil cooler.
Mow lawns as often as needed keeping grass height between 2 ½ and 3 inches.


Pinching, pruning and shaping is the motto of the July garden.
Prune arborvitae, junipers and boxwood once new growth has emerged and expanded the shape of the plant. When pruning, shape shrubs so light can reach all parts of the plant. It is important to do this chore in July or early August, so the plants have enough time to put on new growth before the first hard freeze.
STOP pinching fall blooming perennials such as asters and chrysanthemums.
But DO dead head your flowering plants, it will increase flower production.


Now that it is hot and we water so often, we fertilize on a weekly basis. The exception being hanging baskets and containers where we fertilize every 2-4 watering’s.

Cut back delphinium and perennial salvia to encourage a second bloom.
Fertilize hybrid tea and standard roses. Remove faded flowers to encourage new blooms. Cut the stem of single flowering roses back to the first 5-leaflet leaf. Prune climbing roses after flowering
Pinch back or disbud dahlias for larger flowers. Remove at least two pair of side buds below the top bud.
Dig and divide: bearded iris and spring blooming poppies. Divide all iris that are crowded and discard old, large or diseased rhizomes
Keep deadheading annuals and perennials to keep the garden neat and flowers blooming.


The more you are watering, the more often you need to be fertilizing.

There is still time to get starts in the ground or replace any plants you may need to.
Tomatoes need consistent watering to prevent blossom end rot and misshapen fruit.
Harvest zucchini when the fruits are 6 to 8″ long. They are at their best at that size.
Replant leaf lettuce and sow seeds of sugar snap peas for a fall harvest.

Diseases and Pests

Control pests using the least toxic measure possible, we carry products that will not hurt humans or animals.
Watch for powdery mildew on garden phlox, roses, squash, etc. Proper pruning will increase air circulation and help prevent powdery mildew, but if you notice it on the plant use a fungicide containing sulphur as a safe and environmentally friendly way to control the disease.

Tomato hornworms and other caterpillars can be easily controlled using Bacillus thurgensis (a bacteria that infects caterpillars, mosquitos, and fungus gnats), which is a biological control. It is also the main ingredient in Mosquito dunks.

Nolo Bait (Nosema locustae) is a microfungi that only infects grasshoppers and certain cricket species.

Check Alberta Spruce and juniper for a sprawling white web; it’s a sign of spider mites. A strong spray of Neem oil will get rid of them.
Insecticidal soap is effective controlling aphids, mealy bugs, and many other soft bodied insects
Both Neem Oil and Insecticidal Soap will help control the massive invasion of Elm Seed Beetles. They are a nuisance pest and only feed on elm seeds, but they will take over your home inside and out, if you do not take immediate action.

Fun terrariums and custom planters

We have lots of plants to create a unique look for your home or office.