Fall is just around the corner – indeed in northern areas Labor Day weekend often sees the first cooler weather arrive, and with it the first hints of fall color. As that color intensifies, our evergreens become more prominent, as their permanent green forms a backdrop to the kaleidoscope of golds and reds that takes over our trees. Once simply background, an evergreen screen or hedge is suddenly thrown into contrast – and its defects can become much more prominent. Just when we want them to look perfect, they may not be. So before the full arrival of fall, and the distractions and other garden work that arrives with it, now is an excellent time to give your hedges and evergreens some attention, so that they will be lush and green, and also so that they will pass through the coming winter unscathed.
Recommendations for Fall Care of Thuja Green Giant
- Fertilizer with a high potassium feed – it toughens your plants for winter
- Use a fertilizer with iron and magnesium – it will enrich the green coloring
- Water deeply right up to freeze up – the best prevention for ‘winter burn’
- Give a last trim in early fall – the perfect backdrop to fall color, and reduced winter damage too
Fall Fertilizer Guidelines for Thuja Green Giant
Through spring and summer, the emphasis in feeding evergreens is on the element nitrogen. This is the element that encourages vigorous, lush growth, and so evergreens need plenty of it to fulfil their promise. Strong, rapid growers like Thuja Green Giant in particular, have enormous potential for spring and summer growth, and three feet a year during its early life is easily achieved. But to do that your plants need plenty of nitrogen. So summer fertilizers for evergreens are packed with it, and N-P-K formulas like 10-8-6 in granular feeds, or 20-5-10 in liquid fertilizers are common.
In fall and through winter your evergreens have different needs, so a shift in formulation is needed. Roots respond to the moisture from fall rain, especially since the ground is still warm, and roots need lots of phosphorus – the ‘P’ in that formula. An increase in that number, or even an application of a high-phosphorus fertilizer for transplanting, is called for. Especially if you have new trees, planted back in spring, and you didn’t add phosphorus at that time, early fall is an ideal moment to use a ‘transplant’ fertilizer. Phosphorus is notorious for not penetrating into the soil, so a granular form needs to be forked into the top layers of soil. Alternatively, use a liquid formulation, where the nutrients will be carried deeper by the water they are dissolved in.
In colder area in particular, winter damage is always a concern. The nutrient potassium – that’s the ‘K’ in the formula – has been repeatedly proven to enhance cold resistance, as well as resistance to sucking insects and fungal diseases. A visit to your local hardware or garden center at this time will usually give you a high-potassium evergreen food for fall, with a lower first number too (that’s the nitrogen, remember). Reducing nitrogen and increasing potassium ‘hardens off’ that summer growth, slowing down your plants so they enter winter tough and resistant. As well, look for supplementary iron and magnesium, which will quickly put a rich green into your foliage, intensifying that beautiful color contrast with the golds of fall.
Fall Watering Recommendations for Thuja Green Giant
The stresses of summer can leave the subsoil dry, and unless you have several days of steady rainfall, your trees can go into winter in soil with a moisture deficit. This in turn will leave your plants more prone to stress, so through fall take steps to prevent that. Deep watering in early September will stimulate root growth, and those soakings should continue through the season, making sure to give one last one before the ground begins to freeze (if it does in your zone). Not only does this keep the roots healthy, and the foliage sturdy and full of moisture, but it gives important winter protection too, especially in colder areas, with young plants, and in exposed locations. Thuja Green Giant is one tough plant, but if the foliage is dry it can burn in cold winter winds and bright sun, when water is drawn from the foliage by the solar heat and cold, dry air. If that happens then that green color will turn to brown, disfiguring your hedge, and spoiling that wonderful green winter color. If the ground freezes then it is harder for the trees to draw up water, and the foliage is more susceptible to this kind of damage. Plenty of water at the roots is your secret weapon against this ‘winter burn’, because moist soil freezes more slowly, or not at all, so water uptake is easier for your trees.
Early fall is an ideal time for the last trim
Since your evergreens are about to become a whole lot more noticeable, it is time to smarten them up for the party. A light trim in early fall will smooth out any defects, and make your hedges and screens look perfect. But it’s not just a matter of visuals. Every time you trim you develop denser growth and a tighter surface on your hedges. With every trimming they become denser and denser, which is what gives hedges that mature look we all strive for. As well though, as is often the case with good gardening habits, it isn’t just a case of visuals. If snow and ice storms are a feature of your winters, then a smooth, dense and clipped surface on a hedge is much less likely to accumulate snow and ice and break apart. Make sure too that you round off the top if you are in a high-snowfall area, or subject to blizzards. The round top will shed snow better, and it is much less likely to collapse under the weight of accumulated snow.
If you follow these simple recommendations, you will be making your plants of Thuja Green Giant – and other similar evergreens too – even more beautiful, as well as giving them the best care possible. They will thank you with beauty and rich green coloring as the perfect backdrop to the colorful activities in your garden that make fall most beautiful of all the seasons.