It ranks at the top of the ranking of the most popular trees for the ornamental garden. The ball trumpet tree 'Nana' boasts beautiful heart-shaped leaves that form a round crown on numerous branches. Grafted on a robust wild base, the masterpiece of ingenious breeders reaches 350-400 cm, the ideal height for the house tree in the small garden. The following answers to frequently asked questions explain how you can professionally cultivate this distinctive crowd-pleaser.
How do I care for a globe trumpet tree in my garden?
The 'Nana' ball trumpet tree is ideal for small gardens as it only grows to a height of 350-400 cm. Planted in a sunny to partially shaded location, it requires regular watering, organic fertilization in spring and winter protection in the first few years.
Planting the ball trumpet tree correctly
In practice, spring has proven to be a good planting time for the globe trumpet tree. As soon as the ground has completely thawed in March/April, dig a planting pit in a sunny to partially shaded location with 1.5 times the volume of the root ball. Add mature compost (€10.00 on Amazon) and horn shavings to the excavation to promote rooting. It is an advantage if you drive in the support post before placing the tree in the middle of the pit. Choose the planting depth so that the ball of soil is only a few centimeters below the garden floor. Finally, water generously and mulch with leaves, grass clippings or bark mulch.
Care tips
If your wish for a wind-protected, warm and bright location is satisfied, the care program for the ball trumpet tree is limited to the following measures:
- Keep the soil constantly moist without causing waterlogging
- An organic starter fertilization in March/April
- In August/September, water with comfrey manure to strengthen frost hardiness
- Prune if necessary in early spring
- Carefully thin out the crown every 1-2 years
In the first few years of life, a Catalpa bignonioides 'Nana' depends on your support in order to survive the cold season unscathed. In late autumn, cover the tree disc thickly with leaves and coniferous twigs. The crown is given a hood made of breathable fleece or is wrapped with jute ribbons.
Which location is suitable?
Since the globe trumpet tree immigrated to us from milder regions of the world, the focus when choosing a location is on these criteria:
- Sunny to semi-shady location
- Warm and especially protected from the wind
- Normal, freshly moist to moderately dry garden soil
A location immune to strong winds is of utmost importance. 'Nana' can easily cope with frosty temperatures on its own. However, if there is strong wind, a he althy wintering period is quickly at risk. In addition, the branches become brittle over the years.
What soil does the plant need?
A ball trumpet tree proves to be undemanding and tolerant of the soil conditions. The decorative tree is content with a place in normal garden soil. It prefers to spread its heart root system in loamy-sandy substrate, fresh-moist to moderately dry.
When is flowering time?
You will look in vain for a flower on a ball trumpet tree. In contrast to its larger brothers, such as the common trumpet tree or the golden trumpet tree, 'Nana' does not produce flowers. This has the advantage that none of the poisonous fruits develop, which is desirable in the family garden.
Cut the ball trumpet tree correctly
While a spherical trumpet tree hardly gains any height, its spherical crown takes on an impressive size over the years. If there is enough space available, pruning is not absolutely necessary as 'Nana' develops the harmonious crown shape independently. In this case, just thin out the branches every 1-2 years. In all other cases, we recommend cutting your Catalpa bignonioides like this:
- Determine an overcast, frost-free day in March/April
- Short the branches in stages to the desired length
- Meanwhile step back repeatedly to decide on further cuts
- Remove all dead wood from the crown at the same time without damaging the trunk bark
Use freshly sharpened, disinfected pruning shears. Place these a few millimeters above a leaf node with each cut. Please be careful not to bruise the bark. If wild shoots sprout from the rootstock, cut them off promptly throughout the entire growing season.
Watering the ball trumpet tree
The sunnier the location, the more extensive the evaporation via the large heart leaves. Consequently, the water requirement is at a medium to high level. Water your globe trumpet tree regularly. To test it, press your thumb into the soil during the morning hours. If the top 3-4 cm feel dry, use the watering can. As long as a Catalpa bignonioides 'Nana' has not yet put on its leaves or is only in the budding phase, it is watered less frequently.
Fertilize the ball trumpet tree properly
The leisurely growth results in a low need for fertilizer. Organic starter fertilization in March/April awakens the spirit of life in the ball trumpet tree. Lightly work in compost, horn shavings, bark humus, horse manure or guano granules with the rake and pour in plenty of water. Further nutrient supply is only necessary if there are deficiency symptoms, such as sparse leaves or pale colors.
Wintering
When young, a globe trumpet tree still lacks the winter hardiness of adult trees. Therefore, protect your beautiful house tree from damage using these precautions:
- Pile a 20-30 cm high layer of leaves on the tree disc, secured with needle twigs
- Wrap the branches with jute ribbons or garden fleece
- Cut and thin out the crown at the earliest from the end of February/beginning of March
In August and September you can strengthen the frost hardiness by repeatedly watering the root disc with comfrey manure. The potassium it contains strengthens the cell walls and lowers the freezing point in the cell sap.
Propagate ball trumpet tree
The popular house tree owes its graceful stature to refinement. The crown is connected to a robust winter base using special finishing techniques. Classic propagation methods for trees, such as cuttings, cuttings or planters, are useless in this case.
Ball trumpet tree in a pot
Cultivating a ball trumpet tree in a pot is accompanied by various imponderables. The top priority is a wind-protected location, as the tree is threatened by wind throw due to its special stature. In addition, it should be ensured that the high water requirements are met. On warm summer days, the substrate dries out so quickly that watering is necessary early in the morning and in the evening. To prevent the root ball behind the container walls from freezing in winter, wrap the pot with bubble wrap and place it on wood. After 2-3 years in the pot at the latest, there should be a place available for 'Nana' in the bed where the tree can freely develop its heart root system.
Is globe trumpet tree poisonous?
Catalposid is found in the leaves and shoots of the globe trumpet tree. This ingredient can cause skin irritation in people who are sensitive to it. We therefore recommend that you wear gloves during all planting and care work. Otherwise, Catalpa bignonioides poses no danger, especially since the pods do not grow with poisonous seeds due to the lack of flowers.