The dotted loosestrife is a wild shrub with striking yellow inflorescences and a long flowering period. This is how to properly plant and care for Lysimachia punctata.
Profile of dotted loosestrife:
Scientific name: Lysimachia punctata
Plant family: primrose family (Primulaceae)
Other names: large yellow loosestrife, spotted loosestrife
Sowing time: April to June
Planting time: spring or autumn
Flowering period: June to September
Location: sunny to partially shaded
Soil quality: sandy to loamy, nutrient rich, humus rich, tolerates lime
These information are for temperate climate!
Use in: flower beds, stand alone, group planting, pond planting, borders, flower garden, natural garden, forest garden
Winter hardiness: hardy, USDA Plant Hardiness Zones: 5 (-26 °C / -15 °F)
Bee and insect friendly: Yes
Plant characteristics and classification of dotted loosestrife
Plant order, origin and occurrence of dotted loosestrife
The dotted loosestrife (Lysimachia punctata), also called large yellow loosestrife or spotted loosestrife, is a hardy plant from the primrose family (Primulaceae) and the genus loosestrife (Lysimachia). The wild perennial, which has meanwhile become naturalized in some countries, is originally found in damp locations in southern and Eastern Europe.
Characteristics of dotted loosestrife
Dotted loosestrife a perennial, herbaceous perennial that can grow up to 100 centimeters (40 in) high, but generally is between 60 and 80 centimeters (24 and 32 in) high. Individually placed plants form runners very quickly, all of which are connected to one another via a common root system. Numerous, upright and unbranched stems sprout from the thick roots. Dotted loosestrife grows and covers bald spots in the garden very quickly. However, the strong growth must be stopped by suitable measures, as the robust perennial otherwise displaces other plants.
Dotted loosestrife copes very well with root pressure, which is why it is also very suitable for underplanting trees and standard trees.
The bright summer green foliage is lively and arranged in layers on the stem. The individual, smooth dull leaves have a lanceolate shape with a broad base, are entire and are rather coarse. In the bottom area, the leaves are longer and wider than at the top of the plant, and they shrink evenly from bottom to top.
The heart of the dotted loosestrife are its bright golden yellow flowers, which appear numerous and lush between June and August. The individual flowers sit close together, in groups of three or four comparatively large individual flowers, on the leaf axils. They form a tiered, large panicle that catches the observer’s eye from afar.
In autumn, the dotted loosestrife forms capsule fruits, which will be self seeding over a large area. The seeds are also spread by wind and thus reach more distant garden areas, or even the neighbour’s garden.
Dotted loosestrife – cultivation and care
Dotted loosestrife feels most comfortable in a sunny to partially shaded location. A lot of sun allows the blossoms to shine even more, but the perennial also gets along well in places with less light.
The magnificent flowering plant is best to place it in loose, nutrient-rich, humus-rich and rather moist soil. Whether this is sandy, clay or loamy, rather poor or heavy, on the other hand, does not matter. Only the water storage capacity should be well developed. Dotted loosestrife needs a lot of water, which is especially important for sunny locations. However, the plant also tolerates dry phases well for a short time.
Mulch the soil, something like a mixture of well-rotted compost and bark mulch, so that the moisture stays longer in the soil. This not only provides the perennial with nutrients, but also reduces care measures.
Planting dotted loosestrife
Young plants are best planted in the bed either in autumn or in spring. The only requirement is that there is no more ground frost and none is expected for the next few weeks.
There is space for about six to eight plants per square meter (10 sq ft.), with a distance of about 30 to 40 centimeters (12 to 16 in) at best.
Dotted loosestrife is very suitable for buckets. Choose a pot that is as wide and deep as possible and add a nutrient-rich humus-based substrate, alternatively mix conventional potting soil with compost, and ensure an even and balanced supply of water and nutrients. With regard to fertilization, it is basically sufficient to replace the plant substrate annually with new substrate. The loosestrife is a runners-forming deep-rooted plant that requires a lot of space in its planter.
Between April and June, sow the seeds of the dotted loosestrife at the desired location. Prepare the soil well, loosen it with a hoe and rake, remove weeds and, if necessary, mix ripe compost into the potting soil. After germination, separate the plants at intervals of approx. 30 centimeters (12 in).
As dotted loosestrife usually germinates very quickly, it is not necessary to pre-cultivate it. If you still want to do it, cultivate the plants on the windowsill at the beginning of March and place them in the garden bed after no more frost occur. Autumn is the right time to plant for rooted cuttings.
Dotted loosestrife likes it moist, which is why it has to be watered regularly in dry locations during the summer months. An additional water supply is not necessary in naturally moist places, for example on the bank of a pond or stream or on a moist meadow.
But be careful: Lysimachia punctata doesn’t like waterlogging. This will lead to root rot and thus to diseases and ultimately to the death of the plants.
If the dotted loosestrife is planted, fertilization is only necessary every two to three years. Compost, which may be mixed with lawn clippings, is suitable for this.
Tip: If the dotted loosestrife is in the bucket, it can absorb less nutrients from the soil and should be fertilized additionally.
A dense and bushy growth is in the nature of the plant, so that a regular topiary will not be necessary. So that the plants do not grow too lush and keep their shape, a prune should be done once a year. Radical pruning is carried out in autumn after the flowering period, when the stems have faded and begin to change color. Remove all parts of the plant to about a hand’s width above the ground.
Tip: If you missed it, you can also cut in spring. However, the plant should not have sprouted yet.
If cutting measures are necessary due to diseases or pests, these can be carried out all year round.
Do not cut if you want to obtain seeds.
Lysimachia punctata is very robust and does not require any further care. In order to keep the dotted loosestrife under control and to prevent the perennial from bothering neighboring plants, you should cut off runners regularly.
The easiest way to propagate dotted loosestrife is by dividing groups of plants that have grown too large. This is best done in late summer or early autumn. Alternatively, a division is possible in spring. To do this, dig up the plants and divide the root stocks with a sharp, clean knife or hedge trimmer. At least two strong shoots should remain per root section.
Alternatively, you can propagate the dotted loosestrife by root runners, which you carefully dig up and separate from the maternal rootstock. You can basically take this measure during the entire growing season.
The third option is sowing. For this, just harvest seeds from the seed heads and sow in the field between April and June, as described above.
Diseases and pests
The robust dotted loosestrife is rarely attacked by pests. Only snails find the young and tender shoots very tasty, which is why putting up a snail fence is a sensible measure.
Even pests as caterpillars and those that suckle plant sap, such as aphids, are rarely found on the dotted loosestrife. Plant swill, especially from comfrey or nettles, helps against these uninvited guests. Caterpillars should also be collected and heavily affected parts of the plant should be generously cut back and disposed of directly in the household waste.
Lysimachia punctata also shows great resistance to diseases. Basically, only rot can become a problem. The main reasons for this are permanently too wet, too cold and / or too dark locations. If the plant shows signs of rot it can sometimes be managed to keep by digging out, by a vigorous pruning of both the upper parts of the plant and the roots, as well as replanting. This occurs, for example, when the plant seems to dry up despite apparently sufficient soil moisture or frequent watering and it also smells musty and the earth is moldy.
Wilted, rotten, yellow or brown discolored sections and leaves should always be cut off thoroughly and disposed of with household waste. Such plant parts can contain fungal or other pathogens that spread magnificently on the compost and infect other garden plants from there.
The plants are hardy down to -26 °C / -15 °F. No additional winter protection is required for outdoor plants during the cold season. However, some preparation for the cold season is still beneficial. This initially affects the pruning in autumn. If the stems are radically shortened before winter, this helps to strengthen the roots and make the dotted loosestrife more resistant. The watering also plays a role. With the frost, the watering is stopped, because the plant withdraws into the roots and no longer absorbs nutrients. If night temperatures drop below 10 °C / 50 °F, watering is only done when the soil appears completely dry.
Use in the garden
In the garden, the dotted loosestrife is mainly used in the perennial bed, either as a lush, overgrown single planting or in combination with other sun-loving perennials such as cranesbill (geranium), purple loosestrife (Lythrum salicaria), sedum, lady’s mantle (alchemilla), phlox, lupin (Lupinus), spiraea or various ferns. Combinations of different types of dotted loosestrife also look very nice.
The distinctive perennial comes into its own wherever other flowering plants hardly thrive: Small embankments, nutrient-poor or otherwise difficult locations, e.g. gravel areas, as well as for border planting, as on garden ponds or along groups of trees, is ideal and creates blooming oases from unsightly patches of garden in no time at all. It is also one of the characteristic flowering perennials of a traditional cottage garden.
Furthermore, the dotted loosestrife is suitable as a durable cut flower for colorful bouquets, especially in combination with different colored summer flowers and grasses .
There are several varieties of Lysimachia punctata.
- ‘Alexander’ is a variety with cream-colored, variegated and pink leaves.
- ‘Golden Alexander’ has leaves with a strong, bright yellow margin. The variety is not as vigorous and tall as ‘Alexander’ and is about 60 centimeters (24 in) high.
- “Ivy Maclean” is a variety with leaves that are dark green and yellow-green.
Is dotted loossestrife poisonous?
Lysimachia punctata is not poisonous for humans, dogs, cats and other animals and is therefore ideal for the family garden. The herb can only be dangerous for small rodents such as rabbits or guinea pigs, which is why runs should not be placed in the immediate vicinity of a plantation. However, the small animals usually avoid the plant on their own.
Dotted loosestrife does not bloom
If the dotted loosestrife does not bloom, this can have various causes. The most common reason for the lack of flowering is a location that is too dark: even if it is often claimed that Lysimachia punctata also thrives in the shade, this information should be treated with caution. The perennial actually needs a lot of sun and warmth for lush flowering, which is why a partially shaded location is necessary, at least.
The second cause of weak or non-blooming is too poor substrate and thus a lack of nutrients. However, you can quickly remedy this situation by administering suitable fertilizers. Compost is very well suited for this, but you can also water the dotted loosestrife with a nutrient-rich plant swill made of comfrey, nettles and rock flour. This also has the advantage of acting much faster than compost. Alternatively, one can prepare a swill made with compost. For this palce some compost in a bucket and pour with water. You can use the swill after 3-4 days as a fertilizer.