Congratulations. You have certainly made the right choice – this spring you are planting Thuja Green Giant. Maybe you are replacing that old hedge, or putting in a brand new one, to give your garden structure. Perhaps its is going to be a screen, to protect you from a busy road, driving winds, or for privacy. It could be that you have planted some specimens to create large vertical accents, or an avenue along a driveway. Whatever your reason, after careful consideration you have chosen the best, and certainly the fastest-growing, evergreen there is. But even the best can use help to perform at the top of its game.

They say the first year is the most important one for babies, and its also true for plants. That first growing season, from the preparation of the planting area to the last trim of the year, will set your plants up for top growth, good health, and a trouble-free life. There are some basic things you can do that will create that good start, so let’s look at some pointers on giving your Thuja Green Giant a terrific first year.

Handling Your New Plants on Arrival

The year starts with planting, and there are some things you can do that will make it a success. Before even that, if you have received your potted trees, and you are not quite ready to plant them, don’t forget to keep the pots moist. If the weather is warm those plants can use a lot of water, and pots may need watering every couple of days. First, don’t leave them in the packaging, but unpack immediately, including removing any string or wrapping. Once you do that, examine the soil in the pots. The chances are it will be a little dry, as plants ship best in that condition. If it is, give the pots a good deep soaking, until water flows from the bottom of the pots. Put them in a partially shaded spot – afternoon shade and morning sun is ideal – for a few days while they recover from the shipping. If you are holding them longer than that, move them into full sun, leaving a foot or so between each plant – don’t crowd them together. Every second day check the soil in a few pots, chosen at random. Once the top couple of inches are dry, water thoroughly, again making sure the water drains out the bottom of the pots. Repeat as necessary until you can do the planting.

Soil Preparation

Don’t be in a hurry to plant – those trees will be fine in the pots, even for a month or more – just as long as you water them. Preparing the planting area well takes time, so don’t rush it. The critical thing is to create a large and deep area of loosened soil, so that the new plants can send out roots to establish a large root zone for water and nutrient collection. You should dig or rototill at least 12 inches down, in a strip at least 3 feet wide if you are planting a hedge. If you just dig a hole a little bigger than the pot, and plant into that, there is a good chance that the surrounding soil is hard and compacted – an inhospitable environment for roots.

As well, adding organic material is always a good idea – it enriches sandy soil and holds water, while improving drainage in wet, clay soils – it’s a win-win for every soil type when you use organic material in your garden.

Soil Conditioners

Especially if your soil is poor and your garden new, adding beneficial soil organisms as a biological supplement is a good idea. Soil may lack the correct bacteria and fungi to release nutrients from the soil, and these soil conditioners will bring them in. Look for a mixture that has mycorrhizal fungi spores in it. These amazing organisms form symbiotic relationships with plants by interacting with their roots. There are two kinds, and both should be in your conditioner. Ectomorphic mycorrhizals grow in a cylinder around the tiniest roots of your plant. Endomorphic mycorrhizals grow right in between the cells of the roots and spread out into the soil. Both forms collect nutrients from the soil and exchange them with the plants. These organisms can really boost growth, and they are best added at planting time. Incorporate them into the soil that you put back around the root balls when planting.

Root Spreading

If your plants have been well-grown, there will be a strong mass of roots in the pot. When you plant, these roots need encouragement to spread outwards, and even more important, they need to be stopped from circling around the stem, becoming girdling roots that can strangle the expanding trunk of your trees.

Fixing this problem is easy – just take sharp knife and cut from top to bottom of the root ball at three or four points around it, cutting through the outermost layer of roots. Sounds scary? Don’t worry, its arborist certified as the correct and best method, so go ahead – it won’t hurt, promise. Instead it will help your trees develop and establish quickly, and prevent problems developing further in the future.

Correct Planting Depth

When planting your trees, plant them in the ground, not underground. In other words, the final level of the plants should put the top of the root-ball at the surface of the soil, not buried several inches underground. Deep planting is a terrible mistake, that can lead to poor growth and future trunk problems. Put soil underneath the root-ball until it is at the same level as the final soil. Kake sure you firm down the soil underneath, so that the root ball doesn’t sink into the ground – it can happen. If your soil is heavy and often wet, planting on a low mound, perhaps 6 inches above the surrounding soil, will improve the air-supply to the roots – an important requirement for all plants.


By far the biggest cause of poor growth and plant loss in the first year is watering problems. Remember how those pots needed regular water? Well for a while after planting that is what you have – pot-sized roots sitting in the earth. Those are the only roots that can bring water into the plant, and that small root ball can dry quickly. When planting, it’s important to firm down the soil around the roots – don’t leave air pockets, as these prevent water moving from the soil into the root-ball.

When watering in the first year, water the area where the root-ball is, and a little further out. Its best to let a hose soak each plant at the stem, and them spread the water outwards. If you just look at the soil surface, it may look damp, but the roots themselves can be dry. Usually twice a week for the first month or so, and then once a week for the rest of the year is ideal.


In that first year, use a liquid hedge fertilizer as directed for the particular one you buy. That is often every two weeks, or once a month. Liquid fertilizers are best in the first year, because the nutrients flow right down to the roots and they are absorbed immediately. Granular and slow-release fertilizers are ideal for later years.


Finally, trim an inch or two of your plants as soon as they start growing, and a couple of times through the season. Waiting until they are fully-grown is a big mistake – you want to build good structure right from the start.


If you follow these tips, at the end of that first season you will see excellent growth and development. In the second year your trees will really take off, and before you know it you will have some real green giants in your garden.