Aprium: Planting, Pruning, Harvest

Description and Botany

The aprium, or Prunus x Aprium, is a fruit bush belonging to the genus Prunus and the Rosaceae family, like the apricot, almond, and peach trees. It is a species resulting from hybridization between the apricot tree and the Pluot or plumcot (a cross between a plum and an apricot). It contains 75% of the plum tree’s genome (Prunus domestica) and 25% of the apricot tree (Prunus armeniaca). Like the Pluot, its hybridization was developed in the late 1980s in California by Chris Floyd Zaiger, a breeder and developer of stone fruit hybrids. The aprium, like its parent the pluot, is a registered trademark of Zaiger’s Genetics. Several generations of cross-breeding were required to create this new fruit. Today, many varieties of aprium with varying precocity have been developed.

The aprium forms a spreading tree reaching 4 to 5 m in height at maturity, which is smaller than an apricot tree. It spreads naturally over time. The branches bear deciduous foliage. The alternate, rounded, green leaves, measuring 6 to 15 cm in length, appear in spring. Attached by a long petiole, they are shiny, irregularly dentate on the margins, and veined.

The flowering of the aprium occurs in March-April, at the beginning of spring, usually before the leaves. It is one of the first flowerings of the year, along with those of apricot and almond trees. Numerous small, typical Rosaceae flowers in white-pink appear solitary at the tips of the year’s shoots. They bloom in the form of cups composed of 5 pedunculate petals surrounded by sepals. Melliferous and nectariferous, they are pollinated by foraging insects.

Most aprium varieties are self-fertile and do not require the presence of an apricot tree nearby to ensure good fruiting. It takes about 3 to 4 years before the first harvest. The flowers are followed by the formation of fruit. Large, rounded fruits about 6 cm in diameter, with velvety skin, appear from June. Their epidermis is a beautiful orange dusted with red, slightly velvety. Their colour, the typical crease running along their epidermis, and their shape resemble that of an apricot. They contain sweet, very fragrant white flesh, with a tangy flavour close to that of apricot, with notes of raspberry, plum, and orange. These fleshy fruits weigh about 75 to 85g and are slightly less juicy than apricots.

Aprium fruit

Main varieties

Aprium Cot'n Candy

This is a vigorous, self-fertile variety. It produces large fruits, weighing 75 to 85g, with orange skin and white flesh of excellent flavour.

• Flowering time May
• Height at maturity 4,50 m

See the product sheet

Planting the aprium

Where to Plant It?

Very hardy, able to withstand temperatures as low as -20°C, the aprium can adapt to all regions of France, provided it is planted in a sunny spot sheltered from northern and eastern winds, which could damage the flowering. Like those of the apricot tree, its flowers are sensitive to spring frosts.

In northern regions of France, plant it against a south-facing wall to protect the tree from the cold.

Like many fruit trees, it thrives in full sun in any light, deep, and well-drained soil, even stony or slightly chalky. Adaptable, it suits many soil types, except waterlogged soils, which encourage disease.

It naturally fits into an orchard but also stands out in an ornamental garden, either as a solitary feature on a short grass meadow or at the back of a flower bed, as its spring flowering is enchanting. It can be grown in open forms (standard, half-standard, or goblet). While most varieties are self-fertile, they will fruit better with an apricot tree planted nearby.

When to Plant It?

The aprium is best planted between October and November, avoiding frost, or alternatively in spring with regular watering to ensure establishment.

How to Plant It?

If planting multiple specimens, space them at least 5 to 6 metres apart. If your soil is too compact and heavy, improve drainage (with gravel, sand, or compost).

• For bare-root plants, soak the roots for a day in rooting slurry
• Loosen the soil deeply
• Remove stones and weeds
• Dig a hole two to three times wider and deeper than the root ball
• Spread a layer of drainage material at the bottom (especially if your soil is heavy)
• Add some well-rotted compost to the bottom of the hole
• Place the root ball and fill with garden soil, gently firming as you go to remove air pockets between the roots and soil
• Create a basin around the base and water generously and regularly to encourage rooting

Maintenance and Pruning of the Aprium

For the first two years after planting, ensure regular watering, allowing the soil to dry out between waterings. After that, it will require less attention, and you’ll only need to water during periods of intense heat.

At the beginning of spring, apply well-rotted compost by lightly scratching it into the surface or use fruit tree fertiliser.

In winter, you can also add a shovel of wood ash, rich in potash, to improve fruiting.

When and how to prune the Aprium?

Pruning the Aprium helps maintain good fruiting. Prune with a sharp and thoroughly cleaned pruning shear, and coat the cuts with pruning sealant to prevent diseases.

Training Pruning

During the first three years, prune with a pruning shear to remove dead branches and those that cross each other, leaving only 5 well-spaced main branches.

→ Read more on the topic: “How to train a fruit tree into a goblet shape?”

Maintenance Pruning

Every year, in autumn or late winter, remove suckers by cutting them close to the main branch and lightly trim the tips of the shoots. Eliminate dead wood and damaged or broken branches, as well as those that cross each other, to thin out the branches.

Fruit Thinning Pruning

In early June, when the fruits begin to form: remove some of them, keeping only the largest. Thinning allows for larger fruits, and you can repeat the process 2 or 3 times.

Diseases and potential pests

The Aprium can be susceptible to various diseases. To combat fungal diseases (powdery mildew, moniliosis) which cause a white coating on the leaves or the withering of the flowers and fruit rot on the tree, treat the tree preventively in spring with sprays of Bordeaux mixture.

To combat rust, which causes yellow and brown spots on the top and underside of the leaves, spray a horsetail decoction or Bordeaux mixture.

Multiplication

The Aprium is propagated by grafting. An apricot tree is typically used as the rootstock. This is a technique that requires a certain level of expertise, and we recommend reserving it for professional gardeners.

When and how to harvest apriums?

The aprium fruits 3 to 4 years after planting. The harvest spreads from late June to August, depending on the regions and varieties. Simply pick the fruits by hand when they are at ripeness, well-oranged and tender to the touch. You can pick them just a little before they reach ripeness; they will continue to ripen after the harvest.

Preservation and Uses

Apriums can be kept for up to five days at room temperature. Once washed, dried, and stoned, they can be frozen.

They are eaten like apricots: fresh, dried, or prepared in desserts, fruit salads, jams, juices, ice creams, or as an accompaniment to savoury dishes.

They are rich in fibre, antioxidants, carotin, vitamins A and C, and trace elements.