We love blue flowers! Who doesn’t? Have you ever wondered why? It might just be because true blue flowers are a real rarity in the plant world. Horticulturists and gardeners alike, frequently refer to purple flowers as ‘blue’ but, as we all know, purple is not really what we are searching for.

There are a few true-blue annuals and perennials like delphiniums, cornflowers, forget-me-nots, and lobelia that will provide you with a temporary fix, but, what about a shrub? Are there any shrubs that will bloom true blue year after year? Hydrangea is what you seek! Hydrangea macrophylla, or Big Leaf Hydrangea, is available in varieties that bloom white, pink, purple and, yes, true blue!

But, oh the disappointment! Have you ever purchased the perfect blue hydrangea, taken it home and planted it, only to have it bloom pink the following Summer? This is not uncommon. The cause is simply a soil pH that is too high. And, there’s an easy and convenient solution…Master Nursery® Hydra Blue! If you have a pink Big Leaf Hydrangea that you would like to turn blue or a blue one that you would like to keep that way, it is important that your soil pH be maintained on the acidic side between 5.2 – 5.5. You may begin lowering your soil pH by applying Hydra Blue in the late Fall, as the plant begins to go dormant for the Winter. Give your hydrangea a second application again in the Spring. As with all soil amenders and fertilizers, be sure to follow the directions as listed on the packaging and ask your Master Nursery Garden Center for additional advice regarding your particular situation and soil pH.

Oh, yes, just one thing we forgot to mention, white hydrangeas will always be white!


The Western United States is a large and diverse region. California, alone, is made up of 16 USDA Hardiness Zones. These zones delineate areas, based on average temperature highs and lows, to use as a guideline when selecting plants that may be grown in a given area. However, in order for a plant to thrive, and not just survive, other factors must be considered such as light, water, humidity, and soil type and nutrition. Within a single mile in California, you can experience high-mountain altitude and low desert heat. It is important to be aware of your individual microclimates to garden successfully. Your local Master Nursery Garden Center is an excellent resource for not only quality plants and gardening products but also for gardening information specific to your zone and microclimate.