Fremontodendron: planting, pruning and care

Botany

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The Fremontodendron is a semi-woody bush native to North America, particularly the warm states of California and Arizona. Due to its robustness as well as its resistance to drought and air pollution, it is often planted along roadsides and highways. It also grows naturally in slopes, scrub, and maquis… In other words, it is not particularly demanding under suitable climate conditions.

Known as Fremontia or Fremont’s tree, this bush is classified either in the Sterculiaceae family or, less commonly, in the Malvaceae family. Nevertheless, it is named after the American general John Charles Frémont (1813-1890), who was the first Republican candidate for the presidency of the United States. A fervent opponent of slavery, he was also a great explorer of the western United States. During his expeditions, as a passionate botanist, he catalogued and collected numerous plants, including the Fremontodendron, which pays tribute to him.

The genus Fremontodendron comprises only two species: Fremontodendron californicum, the most commonly cultivated, and Fremontodendron mexicanum, native to northwestern Mexico, listed among the endangered species in California. The latter produces orange-yellow flowers.

This evergreen bush can reach a height of 2 to 5 m with a spread of 2 to 3 m in our latitudes. In its natural habitat, it can grow up to 9 m tall. With a fairly rapid growth rate, the Fremontodendron has semi-woody branches that easily arch to climb if provided with support against a wall. Lacking a climbing mechanism (thorns, suckers, tendrils…) like most climbing plants, the Fremontodendron will need to be trained as it develops, for example, using taut wires. If not trained against a wall, it can be treated as a bush provided it is pruned in the early years to encourage branching and achieve a more compact, upright habit. These branches are covered with a greyish to dark brown scaly bark.

The Fremontodendron features evergreen foliage that is usually dark green on the upper side and light green underneath. The leaves, palmatilobate and alternate, visually resemble those of the vine, but they take on a light brown colour on the underside due to the hairs covering them. They have a diameter of 5 to 7 cm. The petiole is also pubescent, as are the young stems.

The undersides of the leaves and the flower buds of the Fremontodendron are irritating.

As for the flowering, it is attractive due to its beautiful golden yellow colour that brightens up any garden, adding luminosity and vibrancy. The flowers, which emerge from oval, downy flower buds, are solitary and axillary. They form a flat cup 4 to 6 cm in diameter. They consist of 5 large, obovate sepals, shiny and waxy in appearance, rather rounded with a pointed tip that overlap. Five yellow stamens with slightly darker anthers emerge from the heart of the flower. The flowers typically bloom from April-May to July. In regions with a mild climate, they may re-bloom in September and October. Particularly melliferous and nectariferous, these bright yellow flowers attract swarms of insects to enjoy the nectar and pollen. They are also delicately scented.

The flowers give rise to fruits that take the form of downy capsules filled with black seeds. These fruits are nestled within the sepals.

The seed capsules of the Fremontodendron.

It is worth noting that the hairs covering the foliage, flower buds, and young shoots can trigger skin, eye, and respiratory irritations, as well as contact dermatitis. Therefore, when pruning the Fremontodendron, it is essential to wear gloves and long-sleeved clothing.
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Our favourite varieties

Fremontodendron californicum

This is the most widespread variety of Fremontodendron, which is covered in lovely golden-yellow flowers in spring and early autumn. Very versatile, it can be grown as a bush with an upright and rounded habit or trained against a wall

• Période de floraison July, August
• Hauteur à maturité 6 m

See the full description

Frémontodendron 'California Glory'

This hybrid Fremontodendron is a remarkable bush known for its orange-yellow flowering in May and June, which sometimes continues into early autumn

• Période de floraison June to November
• Hauteur à maturité 6 m

See the full description

Planting

Where to Plant the Fremontodendron?

Due to the irritating character of its leaves, young shoots, and flower buds, it is advisable to plant the Fremontodendron in a location away from all daily traffic. Similarly, children should be kept away from this bush, which is otherwise easy to care for.

Ideally, if you wish to train it, install it against a wall or fence facing south or south-west. It will benefit from the full sun necessary for its development. Additionally, its bright yellow flowering will be all the more vibrant there. A sturdy support system made of wire and hooks should be placed on the wall. If you want to grow it as a bush, it can be planted at the back of a border or as a standalone to fully showcase its golden yellow flowers. The Fremontodendron can also be grown in a pot or container on a large balcony, terrace, or patio. Wherever it is planted, it must be sheltered from the coldest winds.

A trained Fremontodendron

It will require a light, ordinary, neutral or alkaline soil, which can be poor, even sandy or stony. The key is that it is perfectly drained, as the Fremontodendron is particularly sensitive to stagnant moisture in winter, which can rot its roots.

The Fremontodendron is very drought-resistant once well established and can tolerate sea spray. Moreover, it has relatively low hardiness. This is why it particularly thrives in the Mediterranean region and the Atlantic coast. Brittany has all the advantages.

When to Plant the Fremontodendron?

The Fremontodendron is best planted in spring, between April and May, so it has time to root before winter.

How to Plant the Fremontodendron?

• Prepare the soil to loosen it well
• Soak the root ball for fifteen minutes in a bucket of water to facilitate potting
• Dig a hole twice as large as the root ball
• Place a layer of gravel at the bottom of the hole to ensure drainage
• Position the Fremontodendron in the hole
• Optionally, add some compost to the extracted soil and fill the hole
• Firm down and water generously.

Growing in a pot is not necessarily easy, but it is possible. You will need to provide your Fremontodendron with a sufficiently large (at least 50 cm in diameter) perforated pot or a large container, drained with a good layer of gravel and filled with potting soil and sand in equal parts.

Maintenance and pruning

Once established, the Fremontodendron requires no special maintenance, being drought-resistant. It is even advisable not to water it at all, keeping it away from automatic watering systems or downspouts. However, for the first two years, it will need a little water, especially during the flowering period, but without excess to avoid drowning the root system.

A bit sensitive to cold, the Fremontodendron may need a good mulch to protect it from frost. Similarly, a winter fleece can be installed if frost is forecasted.

If the Fremontodendron is trained, it is essential to tie the branches as they grow. However, pruning is unnecessary, although you can remove damaged or dead branches. If it is grown as a bush, pruning becomes crucial to allow it to branch from the base. This pruning takes place at the end of flowering, around September. Don’t forget your gloves and long sleeves during this operation.

→ Learn more with our tutorial: How to train and prune the Fremontodendron?

The Fremontodendron is not susceptible to any pests or diseases.

Multiplication: propagation by cuttings and sowing

With a relatively short lifespan, Fremontodendron will need to be propagated to ensure its longevity. Two methods, more or less random, are possible.

Propagation by Cuttings

This propagation by semi-ripe cuttings is done in summer, between July and September.

• Prepare pots filled with light potting soil and sand
• Take semi-ripe cuttings, that is, shoots from the current year, without flowers, about 15 cm long
• Remove the lower leaves, leaving only two
• Plant the cuttings in the substrate
• Firm the soil with your fingers and water gently without saturating the substrate
• Place the pots outside in the shade.

In October, the cuttings are placed under a frame. In spring, the cuttings will be planted in pots to spend a year there. They will be planted in the ground the following spring.

Sowing Seeds

• Harvest the seeds contained in the capsules at the end of flowering, that is, between September and October
• Store them in the refrigerator or in sand outside
• In spring, fill pots with a mixture of special seed compost and sand
• Soak the seeds in water for 24 hours
• Place the seeds on the surface and cover with a layer of sifted compost
• Mist
• Place the pots in a room at 19 °C

The substrate should remain moist without being waterlogged.

Uses and Associations

Fremontodendron is an easy-to-train bush, perfect for climbing along a brick wall or a wooden fence. Its yellow flowering will create a stunning effect. It can easily be paired with perennial plants that have mauve or violet blooms to plant at its base. Fremontodendron pairs very well with lavender, Siberian irises, and thyme, which thrive under the same growing conditions. You can also plant a Pittosporum tenuifolium with green-yellow foliage, such as ‘Gold Star’ or ‘Golden Ball’.

For more pairing ideas, check out Éric’s article: associating Fremontodendron.