I planted a honeysuckle vine from a pot that also contained creeping jenny. This honeysuckle is in Washington state. I planted in ground a year ago. It was approximately 4' tall at the time. The creeping jenny took off and is thick around the base of the vine. Now the leaves on the honeysuckle are yellow and some have dried. Flower production was minimal this summer. Should I remove the creeping jenny? It seems to be comingled with the roots of the honeysuckle. Or is it a nitrogen problem?
Creeping jenny (Lysimachia nummularia) is invasive in parts of North America. It is often more invasive in the northeast than the northwest, but there are some parts of coastal Washington and Oregon where it can be highly invasive as well. Also, outside these areas it can be aggressive in the garden if there is a lot of irrigation.
Whether or not it is competing with your honeysuckle might depend on what species it is, i.e. it is probably more likely to compete with the vining honeysuckles that have a habit of shallow, ground-level roots, and less likely to compete with deeper-rooting honeysuckles.
However if I were in your position I would prioritize removing it just because it is a plant that is known to be invasive in your area. This would especially be true if you are located in to the more high-rainfall, humid parts of the state, like around Puget sound, as these are the areas where it is most likely to be invasive.
Lastly, if you're having trouble growing the honeysuckle, it could be that it's not in the right conditions. I don't know what species you're trying to grow, but in your region I would probably only try to grow Lonicera ciliosa, Lonicera hispudula, Lonicera involucrata, or in more arid parts of the state, Lonicera utahensis. Most other honeysuckles are either going to be hard to grow, or potentially invasive. As for what would be wrong with conditions though, you'll get a very different answer depending on what species you're trying to grow and where you're located!
Creeping Jenny (Lysimachia nummularia) is commonly used in pots and as ground cover, in combination with other plants. There is nothing inherently wrong with the roots of plants mingling (in fact it's inevitable), as long as their combined needs are still met. I doubt your Honeysuckle is suffering specifically due to Creeping Jenny but rather because of competition in general.
Make sure the container is comfortably big enough for the Honeysuckle vine, with extra space for the Creeping Jenny. Consider removing some of the Creeping Jenny around the Honeysuckle now, while the vine is getting better established, it should regrow easily later on.
Ensure the drainage in the container is good so that the soil can remain moist without being waterlogged. Apply an organic mulch and/or a liquid plant food to ensure there are sufficient nutrients for both plants. If the soil in the pot is several years old then thing about emptying it and replanting in fresh compost. Make sure the pot is in a suitable location. Both Honeysuckle and Creeping Jenny will tolerate some shade, but not deep shade.
Hope this helps, good luck 🤞🌱
If you only planted the honeysuckle last year, it may be that it hasn't had sufficient water to settle in properly, especially as, being taken from a pot, it likely had a solid root ball which may not yet have 'broken out' to spread its roots far and wide. If the root ball was solid and large and had been in the previous pot for good while, it needed extra water during hot dry spells this year, of the order of a few gallons applied directly to the ground at the base of the plant, once a week. The first year is particularly critical when a plant is transferred to the ground in terms of watering. Once the plant puts out new roots, spreading over an area below ground, it will be able to seek out whatever it needs itself, but until that happens, keep it well supplied with water. Don't fertilize now, wait till next spring, and keep it watered as necessary during next spring/summer. After that, it should have settled in...
The Lysimachia in and of itself won't be killing your honeysuckle, but it will have been competing for water.