I planted this rose tree in a large container last week and since then its been having issues on the leaves. Not sure if it is too much/too little water/fertilizer or what. The sick leaves are very dry and brittle. Its not occuring on a lot of leaves but i see a few every couple days. Thank you!

Looks like sunburn to me.

If the leaves are dry, you need to check the soil moisture within the pot. You should keep the soil moist. You can test it by sticking your index finger down into the soil to feel how moist or dry it is a couple of inches down. If the pot is drying out too fast, you can water it more often, or position it where it will get less sun (but less sun can affect blooms).

Pots can dry out fast, depending on what they are made of, how many drainage holes they have, how large those holes are, and how large the pot is in comparison with the rose's root mass. For example, unglazed clay pots, such as those made of terra cotta, can dry out fast because they wick the moisture away from the inside to the outside of the pot. Glazed pots and plastic pots will not dry out as fast. Roses often need a larger pot than some people imagine.

For additional feedback, please let us know where you are located, and what your weather has been like.

What Mike Said.

Also, some peat based soils are difficult to get wet and rewet once they dry our. If this is the case with your medium, a simple watering may not do it to start. Normally roses do not like to sit in water, but if the soil isn't moist all the way through you might consider standing the pot in water until it wicks it up and hydrates all the peat....or slowly water bit by bit.

Knowing where you are would really help. If it's very hot there, like it has been in many states this summer, you may need to shade it during the hottest part of the day.

It is impossible to plant a rose either in a container or in the ground without damaging some of the root system. In a sense, this makes the root system inefficient to support the top growth.

The first thing a rose does is grow roots and then it starts sending more moisture to the top growth. During that period, the top growth will look stressed.

The easy way to determine if you need to water a container rose is to lift the side of the pot ... if it's not too large. If it feels "heavy" the soil in the pot is moist enough. Since roses don't like to grow in saturated soil, you water when the pot feels "light".

With some roses, depending on the type of container and depending on the rose, you will end up watering every day during the hottest part of the season because these are what I call "thirsty roses". With other roses and different types of containers, you may end up watering every other day or even every few days. By lifting the pot, you know when it's time to water.

Sometimes once soil in pots dry out they can develop dry spots that cannot absorb moisture or water and deprive some of the roots from water. An option to help gardeners water thirsty plants in pots and gardens a watering system is available with small hoses and emitters , using timers. Set the battery operated timers for all the pots and the work allowed for watering is automatic, less chance for soil dry outs. There are also gallon counter attachments for hoses to keep a check on amounts of water used.

For the past 25 years I have watered my pots and garden with several soaker hoses with emitters that are designed for the purpose to water areas set by zones (ie:front yard west.) All operated on timers using batteries. Never had a issue with any plants, hoses or timers.

Another watering option instead of timers added to the hoses for watering zones and replacing batteries, I have switched to a program on iPad/ IPhone called b-hyve for the past few years. Everything is watered the night before on timed sequences set for each garden zone. Some plants in pots are on a drip system and some are watered more than once a day depending on the temps. The program also has a weather report that allows for rain/heat forecasts and the watering is monitored accordingly. The program has many options designed to use water efficiently and keep plants happy.

With the automatic watering system either battery operated or on IPAD/IPHONE it's easier to leave the house for a couple of days without the worry of loosing plants . Just FYI 🐝

If you have a choice of setting your containers on concrete or putting them on grass (bad for the grass) or soil, avoid the concrete. Concrete or other hard surfaces absorb the heat of the sun on summer days. If concrete is a must, fashion a little riser with available materials to get the pot off the hot surface. Bottom line, don't cook your roses. :-)
David